53 results on '"Kucharski LC"'
Search Results
2. Coping with dry spells: Investigating oxidative balance and metabolic responses in the subtropical tree frog Boana pulchella (Hylidae) during dehydration and rehydration exposure.
- Author
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de Amaral M, Von Dentz MC, Cubas GK, de Oliveira DR, Simões LAR, Model JFA, Oliveira GT, and Kucharski LC
- Subjects
- Animals, Antioxidants metabolism, Liver metabolism, Adaptation, Physiological, Catalase metabolism, Brain metabolism, Oxidation-Reduction, Anura metabolism, Anura physiology, Dehydration metabolism, Oxidative Stress
- Abstract
In the face of climate change, understanding the metabolic responses of vulnerable animals to abiotic stressors like anurans is crucial. Water restriction and subsequent dehydration is a condition that can threaten populations and lead to species decline. This study examines metabolic variations in the subtropical frog Boana pulchella exposed to dehydration resulting in a 40% loss of body water followed by 24 h of rehydration. During dehydration, the scaled mass index decreases, and concentrations of metabolic substrates alter in the brain and liver. The activity of antioxidant enzymes increases in the muscle and heart, emphasizing the importance of catalase in the rehydration period. Glycogenesis increases in the muscle and liver, indicating a strategy to preserve tissue water through glycogen storage. These findings suggest that B. pulchella employs specific metabolic mechanisms to survive exposure to water restriction, highlighting tissue-specific variations in metabolic pathways and antioxidant defenses. These findings contribute to a deeper understanding of anuran adaptation to water stress and emphasize the importance of further research in other species to complement existing knowledge and provide physiological tools to conservation., Competing Interests: Declaration of competing interest The authors affirm that they do not have any competing financial interests or personal relationships that could have influenced the study presented in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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3. Gluconeogenesis in frogs during cooling and dehydration exposure: new insights into tissue plasticity of the gluconeogenic pathway dependent on abiotic factors.
- Author
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de Amaral M, Von Dentz MC, David SM, and Kucharski LC
- Subjects
- Animals, Liver metabolism, Kidney metabolism, Kidney physiology, Muscles metabolism, Muscles physiology, Male, Gluconeogenesis physiology, Anura physiology, Anura metabolism, Cold Temperature, Dehydration physiopathology
- Abstract
Anurans undergo significant physiological changes when exposed to environmental stressors such as low temperatures and humidity. Energy metabolism and substrate management play a crucial role in their survival success. Therefore, understanding the role of the gluconeogenic pathway and demonstrating its existence in amphibians is essential. In this study, we exposed the subtropical frog Boana pulchella to cooling (-2.5°C for 24 h) and dehydration conditions (40% of body water loss), followed by recovery (24 h), and assessed gluconeogenesis activity from alanine, lactate, glycerol and glutamine in the liver, muscle and kidney. We report for the first time that gluconeogenesis activity by 14C-alanine and 14C-lactate conversion to glucose occurs in the muscle tissue of frogs, and this tissue activity is influenced by environmental conditions. Against the control group, liver gluconeogenesis from 14C-lactate and 14C-glycerol was lower during cooling and recovery (P<0.01), and gluconeogenesis from 14C-glutamine in the kidneys was also lower during cooling (P<0.05). In dehydration exposure, gluconeogenesis from 14C-lactate in the liver was lower during recovery, and that from 14C-alanine in the muscle was lower during dehydration (P<0.05). Moreover, we observed that gluconeogenesis activity and substrate preference respond differently to cold and dehydration. These findings highlight tissue-specific plasticity dependent on the nature of the encountered stressor, offering valuable insights for future studies exploring this plasticity, elucidating the importance of the gluconeogenic pathway and characterizing it in anuran physiology., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)
- Published
- 2024
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4. Metabolic changes in the subtropical frog Boana pulchella during experimental cooling and recovery conditions.
- Author
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de Amaral M, Von Dentz MC, Ressel Simões LA, Vogt É, Heiermann D, Fischer P, Colombo P, and Kucharski LC
- Abstract
Frogs have developed biochemical and physiological adaptations to occupy diverse ecological niches on Earth successfully. Survival in frozen states is a fascinating strategy made possible by evolving adaptations to produce cryoprotectant solutes. The hylid frog Boana pulchella thrives in South American regions with cold climates, remaining active while enduring sporadic subzero temperatures during winter. The species' metabolic changes during subzero exposure remain unclear. Therefore, we exposed B. pulchella to cooling and recovery, assessing plasma and tissue metabolite changes. Cooling significantly reduced urea concentrations in plasma (P = 0.033), muscle (P = 0.001), heart (P = 0.009), and brain (P = 0.041) compared to acclimation. Liver glucose oxidation and glycogen synthesis were lower in cooling and recovery than in acclimation (P < 0.0001 and P = 0.0117, respectively). Muscle glycogen synthesis was lower in recovery than acclimation (P = 0.0249). These results demonstrate B. pulchella's physiological strategies during subzero exposure, likely reflecting species-specific evolutionary adaptations for brief subzero exposures that enable winter survival in its natural habitat., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
- Published
- 2023
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5. Female Wistar rats present particular glucose flux when submitted to classic protocols of experimental diabetes.
- Author
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Rocha DS, Dentz MV, Model JFA, Vogt EL, Ohlweiler R, Lima MV, de Souza SK, and Kucharski LC
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- Humans, Rats, Female, Animals, Rats, Wistar, Blood Glucose, Streptozocin metabolism, Streptozocin therapeutic use, Reproducibility of Results, Liver metabolism, Glucose metabolism, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental metabolism
- Abstract
Background: Type 1 diabetes mellitus is a prevalent autoimmune disease worldwide. The knowledge of female particularities in metabolic dysfunction is of fundamental importance, leading to better choices for human therapy candidates. The aim of this study is to investigate the glucose flux peculiarities of female rats submitted to two classic experimental diabetes protocols., Methods: Female Wistar rats, 60 days old, were used to evaluate biochemical and hormonal serum parameters, in addition to skeletal muscle and liver energy stocks and
14 C-glucose and14 C-alanine flux. Two different protocols, multiple (25 mg/kg dose) and single (65 mg/kg dose) intraperitoneal streptozotocin, were compared considering the alterations presented 48 h and 30 days after the drug administration., Results: The results showed few indicators of muscle and liver metabolic imbalance. High-single streptozotocin dose promoted 97% and 41% lower glycogen levels in liver and muscle respectively. Multiple-low streptozotocin dose promoted 63% lower lipid synthesis in liver. After 30 days, diabetic animals presented hyperglycaemia in both protocols, 589.5 (529.3/642.3) mg/dL to high-single dose and 374.2 (339.3/530.6) mg/dL to multiple-low dose. However, they did not present lower insulin levels, alterations on muscle glucose uptake, nor higher hepatic gluconeogenesis., Conclusion: In conclusion, this study demonstrates that females, at least Wistar rats, are less responsive to classic diabetes protocols established in literature, so mechanisms of experimental diabetes for females need more investigation. After which, therapeutic candidates should be evaluated in such a way sex bias does not present itself as a factor that hinders reproducibility in human studies., Competing Interests: Conflicts of interest None., (Copyright © 2022 Chang Gung University. Published by Elsevier B.V. All rights reserved.)- Published
- 2023
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6. Acute effects of a single moderate-intensity exercise bout performed in fast or fed states on cell metabolism and signaling: Comparison between lean and obese rats.
- Author
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Vogt ÉL, Von Dentz MC, Rocha DS, Model JFA, Kowalewski LS, Silveira D, de Amaral M, de Bittencourt Júnior PIH, Kucharski LC, Krause M, and Vinagre AS
- Subjects
- Animals, Male, Rats, Glucose metabolism, Glycogen metabolism, Health Promotion, Insulin metabolism, Muscle, Skeletal metabolism, Obesity metabolism, Triglycerides metabolism, AMP-Activated Protein Kinases metabolism, Sirtuin 1 metabolism
- Abstract
Aims: Although the benefits of exercise can be potentiated by fasting in healthy subjects, few studies evaluated the effects of this intervention on the metabolism of obese subjects. This study investigated the immediate effects of a single moderate-intensity exercise bout performed in fast or fed states on the metabolism of gastrocnemius and soleus of lean and obese rats., Main Methods: Male rats received a high-fat diet (HFD) for twelve weeks to induce obesity or were fed standard diet (SD). After this period, the animals were subdivided in groups: fed and rest (FER), fed and exercise (30 min treadmill, FEE), 8 h fasted and rest (FAR) and fasted and exercise (FAE). Muscle samples were used to investigate the oxidative capacity and gene expression of AMPK, PGC1α, SIRT1, HSF1 and HSP70., Key Findings: In relation to lean animals, obese animals' gastrocnemius glycogen decreased 60 %, triglycerides increased 31 %; glucose and alanine oxidation decreased 26 % and 38 %, respectively; in soleus, triglycerides reduced 46 % and glucose oxidation decreased 37 %. Exercise and fasting induced different effects in glycolytic and oxidative muscles of obese rats. In soleus, fasting exercise spared glycogen and increased palmitate oxidation, while in gastrocnemius, glucose oxidation increased. In obese animals' gastrocnemius, AMPK expression decreased 29 % and SIRT1 increased 28 % in relation to lean. The AMPK response was more sensitive to exercise and fasting in lean than obese rats., Significance: Exercise and fasting induced different effects on the metabolism of glycolytic and oxidative muscles of obese rats that can promote health benefits in these animals., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
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7. Seasonal variations in the intermediate metabolism in South American tree-frog Boana pulchella.
- Author
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de Amaral M, Von Dentz MC, Ohlweiler R, Hoff MLM, Heiermann D, Colombo P, and Kucharski LC
- Subjects
- Animals, Brazil, Energy Metabolism physiology, Glucose metabolism, Male, Seasons, Anura physiology
- Abstract
Seasonal metabolic changes can be observed in many anurans' species. In subtropical environments with environmental temperatures variations, the temperature is a factor that can influence the extent and intensity of activity in many anuran species. Nonetheless, some species of subtropical frogs may remain active throughout the year. Boana pulchella, a subtropical species, seems to be able to survive low temperatures and remain reproductively active even in the coldest months. Therefore, we hypothesized that B. pulchella presents seasonal changes in the energy metabolism to sustain activity during all year. This study evaluated the main energy substrate levels and metabolism of B. pulchella in plasma, liver and muscle of male individuals collected in winter, spring, summer and fall in the state of Rio Grande do Sul, Brazil. Our results showed that B. pulchella has a higher glycolytic oxidation rate in liver (P = 0.0152) and muscle (P = 0.0003) and higher glycogenesis from glucose in muscle (P = 0.0002) in summer, indicating the main energy substrates in this season is glucose. The higher muscle glycogen (P = 0.0008) and lower plasma glucose in fall (P = 0.0134) may indicate an anticipatory regulation for storing to the most thermally demanding cold period: winter. These results indicated seasonal differences in the main energy substrates, and these metabolic changes among seasons can be part of a metabolic adjustment allowing maintenance of reproductive activity all year in Boana pulchella species., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
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8. Pyometra-associated insulin resistance assessment by insulin binding assay and tyrosine kinase activity evaluation in canine muscle tissue.
- Author
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Pöppl ÁG, Valle SC, Mottin TS, Leal JS, González FHD, Kucharski LC, and Da Silva RSM
- Subjects
- Animals, Dogs, Female, Muscles metabolism, Phosphorylation, Protein-Tyrosine Kinases metabolism, Dog Diseases metabolism, Insulin Resistance, Insulins metabolism, Pyometra metabolism, Pyometra veterinary
- Abstract
Diestrus is associated with insulin resistance in bitches and pyometra can further impair insulin sensitivity. This study aimed to compare insulin sensitivity, insulin binding, and tyrosine kinase activity in bitches in anestrus, diestrus, or with pyometra. Patients submitted to elective ovariohysterectomy were divided into anestrus (n = 11) or diestrus (n = 13) according to reproductive history, vaginal cytology, and uterine histology. The group pyometra (n = 8) included bitches diagnosed with the disease based on clinical presentation and abdominal ultrasound findings and further confirmed by uterine histopathology. All patients were submitted to an intravenous glucose tolerance test (IVGTT) before ovariohysterectomy, and rectus abdominis muscle samples were collected during surgery for plasmatic membrane suspension preparation. Muscle-membranes were submitted to cold saturation insulin binding assay for dissociation constant (Kd) and maximum binding capacity (Bmax) determination, as well as exogenous substrate Poly (Glu: Tyr 4:1) phosphorylation assay for basal tyrosine kinase evaluation. Bitches with pyometra showed higher basal insulin (P < 0.001) and higher area under the curve (AUC) for insulin (P = 0.01) and glucose (P < 0.001) response during the IVGTT in comparison with bitches in anestrus or diestrus. Diestrus (P < 0.0001) and pyometra (P = 0.001) were associated with reduced tyrosine kinase activity in comparison with anestrus. No differences were documented in Kd and Bmax results for the low-affinity/high-capacity insulin receptors; however, high-affinity/low-capacity insulin receptors showed higher Kd and Bmax results in bitches in diestrus or with pyometra (P < 0.05) in comparison with anestrus. Despite the pyometra group showed the highest Kd values (P < 0.01), its Bmax results did not differ from the diestrus group (P > 0.05). Diestrus' higher Kd values and reduced tyrosine kinase activity in muscle tissue were compensated by increased total insulin binding capacity. Absent differences in IVGTT results between diestrus and anestrus bitches corroborate this finding. However, in bitches with pyometra, the highest Kd values were not compensated by increased total insulin binding capacity. This finding was associated with insulin resistance and glucose intolerance in IVGTT results. Moreover, pyometra resolution restored insulin sensitivity and glucose tolerance. These features can play a key role in pyometra-associated CDM, as well as in diabetic remission after pyometra resolution., (Copyright © 2021. Published by Elsevier Inc.)
- Published
- 2021
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9. Is the beta estradiol receptor receiving enough attention for its metabolic importance in postmenopause?
- Author
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Rocha DS and Kucharski LC
- Subjects
- Adipose Tissue metabolism, Disease Susceptibility, Estrogens metabolism, Female, Gene Expression Regulation, Humans, Metabolic Diseases etiology, Metabolic Diseases metabolism, Neoplasms drug therapy, Neoplasms etiology, Neoplasms metabolism, Organ Specificity, Receptors, Estradiol genetics, Receptors, Estrogen metabolism, Signal Transduction, Biomarkers, Postmenopause metabolism, Receptors, Estradiol metabolism
- Abstract
The relationship between menopause and the development of metabolic diseases is well established. In postmenopause women, there is an expansion of visceral white adipose tissue (WATv), which highly contributes to the rise of circulating lipids. Meanwhile, muscle glucose uptake decreases and hepatic glucose production increases. Consequently, in the pancreas, lipotoxicity and glycotoxicity lead to deficient insulin production. These factors initiate an energy imbalance and enhance the probability of developing cardiovascular and metabolic diseases. Although the activation of estradiol receptors (ER) has been shown to be beneficial for the WAT stock pattern, leading to the insulin-sensitive phenotype, authors have described the risk of these receptors' activation, contributing to neoplasia development. The selective activation of beta-type ER (ERβ) seems to be a promising strategy in the treatment of energy imbalance, acting on several tissues of metabolic importance and allowing an intervention with less risk for the development of estrogen-dependent neoplasia. However, the literature on the risks and benefits of selective ERβ activation still needs to increase. In this review, several aspects related to ERβ were considered, such as its physiological role in tissues of energy importance, beneficial effects, and risks of its stimulation during menopause. PubMed, SciELO, Cochrane, and Medline/Bireme databases were used in this study., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)
- Published
- 2021
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10. Adipose tissue of female Wistar rats respond to Ilex paraguariensis treatment after ovariectomy surgery.
- Author
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Rocha DS, Argenta Model JF, Von Dentz M, Maschio J, Ohlweiler R, Lima MV, Khal de Souza S, Sarapio E, Vogt ÉL, Waszczuk M, Martiny S, Bassani VL, and Kucharski LC
- Abstract
Background and Aim: Metabolic disturbances are known for their increasing epidemiological importance. Ilex paraguariensis presents a potential option for mitigating lipid metabolism imbalance. However, most of the literature to date has not considered sex bias. This study aimed to evaluate the effect of Ilex paraguariensis on the metabolism of different adipose tissue depots in males and females., Experimental Procedure: After ovariectomy, female Wistar rats received daily treatment with the extract (1 g/kg) for forty-five days. Biochemical serum parameters and tissue metabolism were evaluated. Oxidation, lipogenesis and lipolysis were evaluated in brown, white visceral, retroperitoneal and gonadal adipose tissues., Results and Conclusion: The results showed that treatment with the extract led to a reduced weight gain in ovariectomised females in comparison to control. The triglyceride concentration was decreased in males. Glucose oxidation and lipid synthesis in visceral and retroperitoneal adipose tissues were restored in ovariectomised females after treatment. The response to epinephrine decreased in visceral adipose tissue of control males; however, lipolysis in females did not respond to ovariectomy or treatment. These findings highlight the enormous potential effects of I. paraguariensis on lipid metabolism, modulating lipogenic pathways in females and lipolytic pathways in males. Furthermore, the sex approach applied in this study contributes to more effective screening of the effects of I. paraguariensis bioactive substances., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 Center for Food and Biomolecules, National Taiwan University. Production and hosting by Elsevier Taiwan LLC.)
- Published
- 2020
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11. Differential glucose and beta-hydroxybutyrate metabolism confers an intrinsic neuroprotection to the immature brain in a rat model of neonatal hypoxia ischemia.
- Author
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Odorcyk FK, Duran-Carabali LE, Rocha DS, Sanches EF, Martini AP, Venturin GT, Greggio S, da Costa JC, Kucharski LC, Zimmer ER, and Netto CA
- Subjects
- Animals, Animals, Newborn, Disease Models, Animal, Male, Rats, Rats, Wistar, 3-Hydroxybutyric Acid metabolism, Glucose metabolism, Hypoxia-Ischemia, Brain metabolism, Neuroprotection physiology
- Abstract
Neonatal hypoxia ischemia (HI) is the main cause of newborn mortality and morbidity. Preclinical studies have shown that the immature rat brain is more resilient to HI injury, suggesting innate mechanisms of neuroprotection. During neonatal period brain metabolism experience changes that might greatly affect the outcome of HI injury. Therefore, the aim of the present study was to investigate how changes in brain metabolism interfere with HI outcome in different stages of CNS development. For this purpose, animals were divided into 6 groups: HIP3, HIP7 and HIP11 (HI performed at postnatal days 3, 7 and 11, respectively), and their respective shams. In vivo [
18 F]FDG micro positron emission tomography (microPET) imaging was performed 24 and 72 h after HI, as well as ex-vivo assessments of glucose and beta-hydroxybutyrate (BHB) oxidation. At adulthood behavioral tests and histology were performed. Behavioral and histological analysis showed greater impairments in HIP11 animals, while HIP3 rats were not affected. Changes in [18 F]FDG metabolism were found only in the lesion area of HIP11, where a substantial hypometabolism was detected. Furthermore, [18 F]FDG hypometabolism predicted impaired cognition and worst histological outcomes at adulthood. Finally, substrate oxidation assessments showed that glucose oxidation remained unaltered and higher level of BHB oxidation found in P3 animals, suggesting a more resilient metabolism. Overall, present results show [18 F]FDG microPET predicts long-term injury outcome and suggests that higher BHB utilization is one of the mechanisms that confer the intrinsic neuroprotection to the immature brain and should be explored as a therapeutic target for treatment of HI., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2020
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12. Female rats are more susceptible to metabolic effects of dehydroepiandrosterone treatment.
- Author
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Hoefel AL, Arbo BD, Vieira-Marques C, Cecconello AL, Cozer AG, Ribeiro MFM, and Kucharski LC
- Subjects
- Adipose Tissue metabolism, Animals, Female, Glucose metabolism, Glycogen biosynthesis, Lipids, Lipogenesis drug effects, Liver metabolism, Male, Models, Animal, Muscle, Skeletal metabolism, Rats, Rats, Wistar, Sex Factors, Adipose Tissue drug effects, Body Weight drug effects, Dehydroepiandrosterone administration & dosage, Liver drug effects, Muscle, Skeletal drug effects
- Abstract
Dehydroepiandrosterone (DHEA) is a steroid hormone that presents several effects on metabolism; however, most of the studies have been performed on male animals, while few authors have investigated possible sex differences regarding the metabolic effects of DHEA. Therefore, the aim of this study was to evaluate the effect of different doses of DHEA on metabolic parameters of male and ovariectomized female Wistar rats. Sex differences were found in the metabolism of distinct substrates and in relation to the effect of DHEA. In respect to the glucose metabolism in the liver, the conversion of glucose to CO
2 and the synthesis of lipids from glucose were 53% and 33% higher, respectively, in males. Also, DHEA decreased hepatic lipogenesis only in females. Regarding the hepatic glycogen synthesis pathway, females presented 73% higher synthesis than males, and the effect of DHEA was observed only in females, where it decreased this parameter. In the adipose tissue, glucose uptake was 208% higher in females and DHEA decreased this parameter. In the muscle, glucose uptake was 168% higher in females and no DHEA effect was observed. In summary, males and females present a different metabolic profile, with females being more susceptible to the metabolic effects of DHEA.- Published
- 2018
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13. Redox and metabolic strategies developed by anterior and posterior gills of the crab Neohelice granulata after short periods of hypo- or hyper-osmotic stress.
- Author
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Fernandes FA, Dutra BK, Mosele F, Araujo ASR, Ferreira GD, Belló-Klein A, Kucharski LC, Vinagre AS, and Da Silva RSM
- Subjects
- Animals, Gills, Hydrogen Peroxide, Oxidation-Reduction, Sodium-Potassium-Exchanging ATPase, Brachyura physiology, Osmotic Pressure, Stress, Physiological
- Abstract
The aim of this study was to identify the response pattern of redox balance, Na
+ /K+ ATPase activity and HSP70 expression in the posterior and anterior gills of the crab Neohelice granulata submitted to hypo- or hyper-osmotic stress for 1 h and 6 h. After 1 h of either type of osmotic stress, there was an increase in catalase activity, but a decrease in GSSG/GSH ratio (oxidized to reduced glutathione ratio) and Na+ /K+ ATPase activity in both gill sets. H2 O2 levels decreased only in the posterior gills. H2 O2 levels and Na+ /K+ ATPase activity remained reduced after 6 h of exposure to either type of osmotic stress in both gill sets. The GSSG/GSH ratio returned to initial levels after 6 h of hyper-osmotic stress, whereas it increased 10 times in both gill sets after hypo-osmotic stress. Furthermore, HSP70 protein expression increased in posterior gills after 6 h of hypo-osmotic stress. H2 O2 levels in tank water decreased after hypo-osmotic challenge and increased after 6 h of hyper-osmotic stress, indicating increased H2 O2 excretion. Therefore, N. granulata gills have redox, metabolic and molecular strategies to deal with rapid osmotic challenges, an important environmental parameter that influences juvenile and adult crab distribution and abundance within different populations., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
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14. Effect of yerba mate (Ilex paraguariensis) extract on the metabolism of diabetic rats.
- Author
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Rocha DS, Casagrande L, Model JFA, Dos Santos JT, Hoefel AL, and Kucharski LC
- Subjects
- Animals, Creatinine blood, Diabetes Mellitus, Experimental blood, Lipids blood, Liver enzymology, Liver metabolism, Male, Muscles metabolism, Rats, Wistar, Transaminases metabolism, Urea blood, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental metabolism, Ilex paraguariensis chemistry, Plant Extracts therapeutic use
- Abstract
The relationship between metabolic disturbances and clinical events related to diabetes is well known. Yerba mate has presented a potential use as preventive and therapeutic agent on diabetes. The aim of this study was to evaluate the effect of yerba mate on different tissues of diabetic rats, focusing on energetic metabolism. Diabetes was induced by streptozotocin, followed by daily yerba mate treatment. After 30 days, the animals were euthanized to evaluate metabolic parameters on liver, adipose tissue, muscle and serum. The results showed mate treatment promoted a decrease in retroperitoneal adipose tissue in healthy animals. Muscle weight returned to control levels in diabetic rats treated with mate. There was improvement on serum glucose, creatinine, urea and total protein levels associated with mate treatment. Muscle parameters, such as glucose uptake and carbon dioxide production, were improved by mate treatment to control levels. The results evidenced the beneficial actions mate can have on metabolic disturbances of diabetes., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)
- Published
- 2018
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15. Protein and lipid metabolism adjustments in silver catfish (Rhamdia quelen) during different periods of fasting and refeeding.
- Author
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Marqueze A, Garbino CF, Trapp M, Kucharski LC, Fagundes M, Ferreira D, Koakoski G, and Rosa JGS
- Subjects
- Adaptation, Physiological, Animal Feed, Animals, Fasting metabolism, Glycogen metabolism, Lipids blood, Male, Muscles, Catfishes physiology, Energy Metabolism physiology, Fasting physiology, Feeding Behavior, Lipid Metabolism physiology
- Abstract
The fish may experience periods of food deprivation or starvation which produce metabolic changes. In this study, adult Rhamdia quelen males were subjected to fasting periods of 1, 7, 14, and 21 days and of refeeding 2, 4, 6, and 12 days. The results demonstrated that liver protein was depleted after 1 day of fasting, but recovered after 6 days of refeeding. After 14 days of fasting, mobilization in the lipids of the muscular tissue took place, and these reserves began to re-establish themselves after 4 days of refeeding. Plasmatic triglycerides increased after 1 day of fasting, and decreased following 2 days of refeeding. The glycerol in the plasma oscillated constantly during the different periods of fasting and refeeding. Changes in the metabolism of both protein and lipids during these periods can be considered as survival strategies used by R. quelen. The difference in the metabolic profile of the tissues, the influence of the period of fasting, and the type of reserves mobilized were all in evidence.
- Published
- 2018
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16. Acute intraperitoneal administration of taurine decreases the glycemia and reduces food intake in type 1 diabetic rats.
- Author
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Gomez R, Caletti G, Arbo BD, Hoefel AL, Schneider R Jr, Hansen AW, Pulcinelli RR, Freese L, Bandiera S, Kucharski LC, and Barros HMT
- Subjects
- Animals, Diabetes Mellitus, Experimental metabolism, Diabetes Mellitus, Type 1 metabolism, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents therapeutic use, Injections, Intraperitoneal, Male, Rats, Wistar, Streptozocin, Taurine administration & dosage, Taurine therapeutic use, Blood Glucose metabolism, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Type 1 drug therapy, Eating drug effects, Hypoglycemic Agents pharmacology, Taurine pharmacology
- Abstract
Taurine, an amino acid with antioxidant and osmoregulatory properties, has been studied for its possible antidiabetic properties in type 1 and type 2 diabetic animals. In type 2 diabetic mice, taurine decreases blood glucose through increased insulin secretion and insulin receptor sensitization. However, insulin is absent in type 1 diabetic individuals. The aim of this study was to evaluate the effects of taurine on parameters related to the energy balance that could explain the metabolic action of this amino acid in type 1 diabetic rats. Control and streptozotocin-induced diabetic rats received saline or taurine (100 mg/kg/day), intraperitoneally, for 30 days. Parameters such as palatable food intake, gastrointestinal transit rate, serum glucose, insulin, leptin, and glucagon levels were measured 60 min after the last taurine administration. Liver, kidneys, heart, and retroperitoneal fat were dissected and weighted. Glycogen levels were measured in the liver and soleus muscle. Our results showed that acute taurine administration decreased glycemia. It also decreased food intake in diabetic rats, without affecting other metabolic parameters. Altogether, our results suggest that in type 1 diabetic rats, taurine decreases blood glucose by a non-insulin-dependent mechanism. Due to the safety profile of taurine, and its effect on glycemia, this amino acid may help to design new drugs to add benefit to insulin therapy in type 1 diabetic individuals., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)
- Published
- 2018
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17. Insulin-like receptors and carbohydrate metabolism in gills of the euryhaline crab Neohelice granulata: Effects of osmotic stress.
- Author
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Trapp M, Valle SC, Pöppl AG, Chittó ALF, Kucharski LC, and Da Silva RSM
- Subjects
- Animals, Area Under Curve, Cattle, Cell Membrane metabolism, Deoxyglucose metabolism, Insulin metabolism, Iodine Radioisotopes metabolism, Male, Phosphorylation, Brachyura metabolism, Carbohydrate Metabolism, Gills metabolism, Osmotic Pressure, Receptor, Insulin metabolism, Stress, Physiological
- Abstract
The present study determined the effect of osmotic stress on the insulin-like receptor binding characteristics and on glucose metabolism in the anterior (AG) and posterior (PG) gills of the crab Neohelice granulata. Bovine insulin increased the capacity of the PG cell membrane to phosphorylate exogenous substrate poly (Glu:Tyr 4:1) and the glucose uptake in the control crab group. The crabs were submitted to three periods of hyperosmotic (HR) and hyposmotic (HO) stress, for 24, 72 and 144 h, to investigate the insulin-like receptor phosphorylation capacity of gills. Acclimation to HO for 24 h or HR for 144 h of stress inhibited the effects of insulin in the PG, decreasing the capacity of insulin to phosphorylate exogenous substrate poly (Glu:Tyr 4:1) and decreasing the glucose uptake. Hyperosmotic stress for the same period of 144 h significantly affected
125 I-insulin binding in the AG and PG. However, HO stress for 24 h significantly reduced125 I-insulin-specific uptake only in the PG. Therefore, osmotic stress induces alterations in the gill insulin-like receptors that decrease insulin binding in the PG. These findings indicate that osmotic stress induced a pattern of insulin resistance in the PG. The free-glucose concentration in the PG decreased during acclimation to 144 h of HR stress and 24 h of HO stress. This decrease in the cell free-glucose concentration was not accompanied by a significant change in hemolymph glucose levels. In AG from the control group, neither the capacity of bovine insulin to phosphorylate exogenous substrate poly (Glu:Tyr 4:1) nor the glucose uptake changed; however, genistein decreased tyrosine-kinase activity, confirming that this receptor belongs to the tyrosine-kinase family. Acclimation to HO (24 h) or HR (144 h) stress decreased tyrosine-kinase activity in the AG. This study provided new information on the mechanisms involved in the osmoregulation process in crustaceans, demonstrating for the first time in an estuarine crab that osmotic challenge inhibited insulin-like signaling and the effect of insulin on glucose uptake in the PG., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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18. Effects of Stanniocalcin-1 on glucose flux in rat brown adipose tissue.
- Author
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Cozer AG, Trapp M, Martins TL, De Fraga LS, Vieira Marques C, Model JFA, Schein V, Kucharski LC, and Da Silva RSM
- Subjects
- Animals, Lipogenesis, Male, Rats, Rats, Wistar, Uncoupling Protein 1, Adipose Tissue, Brown metabolism, Glucose metabolism, Glycerophosphates metabolism, Glycolysis, Glycoproteins physiology
- Abstract
The present work assesses in vitro the role of human Stanniocalcin 1 (hSTC-1) in
14 C-glucose metabolism in brown adipose tissue (BAT) from fed rat. In the fed state, hSTC-1 decreases the incorporation of14 C from glucose into lipids in the rat BAT. The data support the hypothesis that the capacity of the glycerol-3-phosphate (G3P)-generating pathway (glycolysis) from glucose is regulated by hSTC-1, decreasing the adequate supply of G3P needed for fatty acid esterification and triacylglycerol (TG) storage in BAT. The results also suggest the effect of hSTC-1 on de novo fatty acid synthesis from pyruvate generated by14 C-glucose in the glycolysis pathway. In addition, by decreasing lipogenesis, hSTC-1 increased ATP levels and these two factors may decrease BAT thermogenic function. The presence of hSTC-1 in the incubation medium did not alter14 C-glucose and14 C-1-palmitic acid oxidation. The uncoupling protein 1 (UCP-1) expression was not altered by hSTC-1 either. In conclusion, hSTC-1 is one of the hormonal factors that control glucose metabolism in BAT in the fed state. The decrease of TG capacity synthesis from14 C-glucose by hSTC-1 compromises the BAT thermogenic capacity. Furthermore, the increase in ATP levels would inhibit a futile cycle via UCP-1, which dissipates oxidative energy as heat., (Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.)- Published
- 2017
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19. Sex-specific effects of dehydroepiandrosterone (DHEA) on glucose metabolism in the CNS.
- Author
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Vieira-Marques C, Arbo BD, Cozer AG, Hoefel AL, Cecconello AL, Zanini P, Niches G, Kucharski LC, and Ribeiro MFM
- Subjects
- Animals, Carbon Radioisotopes, Cerebral Cortex metabolism, Dehydroepiandrosterone administration & dosage, Deoxyglucose metabolism, Hippocampus metabolism, Hypothalamus metabolism, Mice, Olfactory Bulb metabolism, Organ Specificity, Oxidation-Reduction, Rats, Rats, Wistar, Sex Characteristics, Absorption, Physiological, Central Nervous System metabolism, Dehydroepiandrosterone metabolism, Glucose metabolism, Glycogen metabolism, Neurons metabolism, Neuroprotection
- Abstract
DHEA is a neuroactive steroid, due to its modulatory actions on the central nervous system (CNS). DHEA is able to regulate neurogenesis, neurotransmitter receptors and neuronal excitability, function, survival and metabolism. The levels of DHEA decrease gradually with advancing age, and this decline has been associated with age related neuronal dysfunction and degeneration, suggesting a neuroprotective effect of endogenous DHEA. There are significant sex differences in the pathophysiology, epidemiology and clinical manifestations of many neurological diseases. The aim of this study was to determine whether DHEA can alter glucose metabolism in different structures of the CNS from male and female rats, and if this effect is sex-specific. The results showed that DHEA decreased glucose uptake in some structures (cerebral cortex and olfactory bulb) in males, but did not affect glucose uptake in females. When compared, glucose uptake in males was higher than females. DHEA enhanced the glucose oxidation in both males (cerebral cortex, olfactory bulb, hippocampus and hypothalamus) and females (cerebral cortex and olfactory bulb), in a sex-dependent manner. In males, DHEA did not affect synthesis of glycogen, however, glycogen content was increased in the cerebral cortex and olfactory bulb. DHEA modulates glucose metabolism in a tissue-, dose- and sex-dependent manner to increase glucose oxidation, which could explain the previously described neuroprotective role of this hormone in some neurodegenerative diseases., (Copyright © 2016. Published by Elsevier Ltd.)
- Published
- 2017
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20. Stanniocalcin 1 Enhances Carbon Flux from Glucose to Lipids in White Retroperitoneal Adipose Tissue in the Fed Rat.
- Author
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Cozer AG, Trapp M, Vieira Marques C, Martins TL, Model JF, Schein V, Kucharski LC, and Da Silva RS
- Subjects
- Adenosine Triphosphate metabolism, Animals, Carbon Dioxide metabolism, Fatty Acids metabolism, Humans, Lipogenesis, Male, Oxidation-Reduction, Rats, Rats, Wistar, Adipose Tissue, White metabolism, Glucose metabolism, Glycoproteins metabolism, Lipid Metabolism
- Abstract
The present work assesses in vitro the role of human Stanniocalcin 1 (hSTC-1) in glucose metabolism in white retroperitoneal adipose tissue (WRAT) from fed rat. In the fed state, hSTC1 increases the incorporation of
14 C from glucose into lipids in the rat WRAT. The increase in lipogenesis capacity supports the hypothesis that the activity of the glycerol-3-phosphate-generating pathway (glycolysis) from glucose is regulated by hSTC-1. The effect of hSTC-1 on de novo fatty acid synthesis and on glucose oxidation in WRAT is supported by an 85 % increase in14 CO2 production from14 C-glucose. The incubation of WRAT in the presence of hSTC-1 maintained the ADP/ATP ratio close to the control group. The presence of hSTC-1 in the incubation medium did not inhibit the lipolytic effect of epinephrine. In conclusion, hSTC-1 is one of the hormonal factors that control glucose metabolism in WRAT in the fed state.- Published
- 2016
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21. Dehydroepiandrosterone protects male and female hippocampal neurons and neuroblastoma cells from glucose deprivation.
- Author
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Vieira-Marques C, Arbo BD, Ruiz-Palmero I, Ortiz-Rodriguez A, Ghorbanpoor S, Kucharski LC, Arevalo MA, Garcia-Segura LM, and Ribeiro MF
- Subjects
- Animals, Cell Line, Tumor, Cell Survival drug effects, Female, Glucose metabolism, Hippocampus metabolism, Humans, Male, Mice, Neurons metabolism, Primary Cell Culture, Dehydroepiandrosterone pharmacology, Hippocampus drug effects, Neurons drug effects, Neuroprotective Agents pharmacology
- Abstract
Dehydroepiandrosterone (DHEA) modulates neurogenesis, neuronal function, neuronal survival and metabolism, enhancing mitochondrial oxidative capacity. Glucose deprivation and hypometabolism have been implicated in the mechanisms that mediate neuronal damage in neurological disorders, and some studies have shown that these mechanisms are sexually dimorphic. It was also demonstrated that DHEA is able to attenuate the hypometabolism that is related to some neurodegenerative diseases, eliciting neuroprotective effects in different experimental models of neurodegeneration. The aim of this study was to evaluate the effect of DHEA on the viability of male and female hippocampal neurons and SH-SY5Y neuroblastoma cells exposed to glucose deprivation. It was observed that after 12h of pre-treatment, DHEA was able to protect SH-SY5Y cells from glucose deprivation for 6h (DHEA 10(-12), 10(-8) and 10(-6)M) and 8h (DHEA 10(-8)M). In contrast, DHEA was not neuroprotective against glucose deprivation for 12 or 24h. DHEA (10(-8)M) also protected SH-SY5Y cells when added together or even 1h after the beginning of glucose deprivation (6h). Furthermore, DHEA (10(-8)M) also protected primary neurons from both sexes against glucose deprivation. In summary, our findings indicate that DHEA is neuroprotective against glucose deprivation in human neuroblastoma cells and in male and female mouse hippocampal neurons. These results suggest that DHEA could be a promising candidate to be used in clinical studies aiming to reduce neuronal damage in people from both sexes., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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22. Effects of sleep restriction during pregnancy on the mother and fetuses in rats.
- Author
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Pardo GV, Goularte JF, Hoefel AL, de Castro AL, Kucharski LC, da Rosa Araujo AS, and Lucion AB
- Subjects
- Animals, Brain embryology, Brain metabolism, Brain-Derived Neurotrophic Factor metabolism, Cholesterol metabolism, Corticosterone blood, Female, Glycogen metabolism, Liver metabolism, Maternal Behavior physiology, Muscles metabolism, Olfactory Perception physiology, Oxytocin blood, Pregnancy, Prolactin blood, Random Allocation, Rats, Reactive Oxygen Species metabolism, Triglycerides metabolism, Weight Gain, Pregnancy Complications metabolism, Sleep Deprivation metabolism
- Abstract
The present study aimed to analyze the effects of sleep restriction (SR) during pregnancy in rats. The following three groups were studied: home cage (HC pregnant females remained in their home cage), Sham (females were placed in tanks similar to the SR group but with sawdust) and SR (females were submitted to the multiple platform method for 20 h per day from gestational days (GD) 14 to 20). Plasma corticosterone after 6 days of SR was not different among the groups. However, the relative adrenal weight was higher in the SR group compared with the HC group, which suggests possible stress impact. SR during pregnancy reduces the body weight of the female but no changes in liver glycogen, cholesterol and triglycerides, and muscle glycogen were detected. On GD 20, the fetuses of the females submitted to SR exhibited increased brain derived neurotrophic factor (BDNF) in the hippocampus, which indicates that sleep restriction of mothers during the final week of gestation may affect neuronal growth factors in a fetal brain structure, in which active neurogenesis occurs during the deprivation period. However, no changes in the total reactive oxygen species (ROS) in the cortex, hippocampus, or cerebellum of the fetuses were detected. SR females showed no major change in the maternal behavior, and the pups' preference for the mother's odor on postpartum day (PPD) 7 was not altered. On GD 20, the SR females exhibited increased plasma prolactin (PRL) and oxytocin (OT) compared with the HC and Sham groups. The negative outcomes of sleep restriction during delivery could be related, in part, to this hormonal imbalance. Sleep restriction during pregnancy induces different changes compared with the changes described in males and affects both the mother and offspring., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2016
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23. Obesity and Hyperlipidemia Modulate Alveolar Bone Loss in Wistar Rats.
- Author
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Cavagni J, de Macedo IC, Gaio EJ, Souza A, de Molon RS, Cirelli JA, Hoefel AL, Kucharski LC, Torres IL, and Rösing CK
- Subjects
- Animals, Male, Periodontitis, Rats, Rats, Wistar, X-Ray Microtomography, Alveolar Bone Loss, Hyperlipidemias, Obesity
- Abstract
Background: A positive association between obesity-associated metabolic disorders (e.g., hyperlipidemia and diabetes) and periodontitis has been demonstrated in the literature. This study evaluates the role of cafeteria diet-induced obesity/hyperlipidemia (CAF) on alveolar bone loss (ABL) in rats., Methods: Sixty male Wistar rats were randomly divided in four groups: control, periodontitis (PERIO), obesity/hyperlipidemia (CAF), and obesity/hyperlipidemia plus periodontitis (CAF+PERIO). Groups CAF and CAF+PERIO were exposed to a high-fat, hypercaloric diet. At week 12, periodontal disease was induced in groups PERIO and CAF+PERIO by ligatures in the upper second molar. The contralateral tooth was considered the intragroup control. Body weight and Lee index were evaluated weekly during the experiment. Serum glucose and cholesterol/triglycerides in the liver were evaluated, and percentage of ABL was measured by microcomputed tomography. Serum tumor necrosis factor (TNF)-α and interleukin (IL)-1β were evaluated by enzyme-linked immunosorbent assay at week 17., Results: Body weight, Lee index, and cholesterol/triglycerides in the liver increased in groups exposed to the cafeteria diet. Groups PERIO and CAF+PERIO exhibited a significantly higher ABL compared to control and CAF groups. The presence of obesity and hyperlipidemia significantly increased ABL in the CAF+PERIO group compared to the PERIO group (53.60 ± 3.44 versus 42.78 ± 7.27, respectively) in the sides with ligature. Groups exposed to CAF exhibited higher ABL in the sides without ligature. No differences were observed among groups for IL-1β and TNF-α., Conclusion: Obesity and hyperlipidemia modulate the host response to challenges in the periodontium, increasing the expression of periodontal breakdown.
- Published
- 2016
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24. Stanniocalcin 1 effects on the renal gluconeogenesis pathway in rat and fish.
- Author
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Schein V, Kucharski LC, Guerreiro PM, Martins TL, Morgado I, Power DM, Canario AV, and da Silva RS
- Subjects
- Animals, Bass genetics, Gene Expression Regulation, Glutamine metabolism, Humans, Intracellular Signaling Peptides and Proteins genetics, Intracellular Signaling Peptides and Proteins metabolism, Kidney Cortex metabolism, Lactic Acid metabolism, Male, Mammals metabolism, Mitochondria enzymology, Phosphoenolpyruvate Carboxykinase (GTP) genetics, Phosphoenolpyruvate Carboxykinase (GTP) metabolism, Rats, Rats, Wistar, Bass metabolism, Fish Proteins metabolism, Gluconeogenesis, Glycoproteins metabolism, Kidney Medulla metabolism
- Abstract
The mammalian kidney contributes significantly to glucose homeostasis through gluconeogenesis. Considering that stanniocalcin 1 (STC1) regulates ATP production, is synthesized and acts in different cell types of the nephron, the present study hypothesized that STC1 may be implicated in the regulation of gluconeogenesis in the vertebrate kidney. Human STC1 strongly reduced gluconeogenesis from (14)C-glutamine in rat renal medulla (MD) slices but not in renal cortex (CX), nor from (14)C-lactic acid. Total PEPCK activity was markedly reduced by hSTC1 in MD but not in CX. Pck2 (mitochondrial PEPCK isoform) was down-regulated by hSTC1 in MD but not in CX. In fish (Dicentrarchus labrax) kidney slices, both STC1-A and -B isoforms decreased gluconeogenesis from (14)C-acid lactic, while STC1-A increased gluconeogenesis from (14)C-glutamine. Overall, our results demonstrate a role for STC1 in the control of glucose synthesis via renal gluconeogenesis in mammals and suggest that it may have a similar role in teleost fishes., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
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25. Serotonin effects in the crab Neohelice granulata: Possible involvement of two types of receptors in peripheral tissues.
- Author
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Inohara ET, Pinto CB, Model JF, Trapp M, Kucharski LC, Da Silva RS, and Vinagre AS
- Subjects
- Animals, Brachyura drug effects, Cyproheptadine pharmacology, Gills drug effects, Gills metabolism, Male, Methiothepin pharmacology, Organ Specificity, Posture, Serotonin Antagonists pharmacology, Arthropod Proteins physiology, Brachyura metabolism, Receptors, Serotonin physiology, Serotonin physiology
- Abstract
In crustaceans, serotonin (5-HT) controls various physiological processes, such as hormonal secretion, color changes, reproduction, and metabolism. Since 5-HT injections cause hyperglycemia, this study was designed to further investigate this action of 5-HT in the crab Neohelice granulate, fed with a high-carbohydrate (HC) or a high-protein (HP) diet. The effects of pre-treatment with mammalian 5-HT receptor antagonists, cyproheptadine and methiothepin, were also investigated. A series of in vivo experiments with (3)H-5-HT was carried out in order to investigate the presence of putative receptors in peripheral tissues. Since gills were the tissue with the highest labeling in in vivo experiments, in vitro studies with isolated anterior and posterior gills were also conducted. Cyproheptadine blocked the hyperglycemic effect of 5-HT in HP-fed crabs. Methiothepin reduced glycogen levels in the anterior gills of HP crabs and partially blocked the 5-HT-like posture. The injection of (3)H-5-HT identified specific binding sites in all the tissues studied and revealed that the binding can be influenced by the type of diet administered to the crabs. Incubation of the anterior and posterior gills with (3)H-5-HT and 5-HT confirmed the specificity of the binding sites. Both antagonists inhibited (3)H-5-HT binding. In conclusion, this study highlights the importance of serotonin in the control of glucose homeostasis in crustaceans and provides evidences of at least two types of 5-HT binding sites in peripheral tissues. Further studies are necessary to identify the structure of these receptors and their signaling pathways., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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26. Sex-related differences in the effects of high-fat diets on DHEA-treated rats.
- Author
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Cecconello AL, Trapp M, Hoefel AL, Marques CV, Arbo BD, Osterkamp G, Kucharski LC, and Ribeiro MF
- Subjects
- Animals, Blood Glucose metabolism, Female, Hyperinsulinism metabolism, Insulin blood, Leptin blood, Lipids blood, Liver drug effects, Liver metabolism, Male, Rats, Rats, Wistar, Risk Factors, Sex Factors, Body Weight drug effects, Dehydroepiandrosterone pharmacology, Diet, High-Fat, Lipid Metabolism drug effects, Obesity metabolism
- Abstract
Several studies have investigated the beneficial effects of dehydroepiandrosterone (DHEA) on lipid and glucose metabolism. However, many of these studies are inconclusive about the effects of DHEA administration on metabolic disorders, and there appear to be sex-related differences in the effects of DHEA treatment. Few animal studies have addressed the effects of DHEA on diet-induced metabolic disorders. The present study sought to ascertain whether sex differences exist in the effects of a high-fat diet (HFD) on weight gain, adiposity, and biochemical and hormonal parameters in DHEA-treated rats. Rats were fed a HFD for 4 weeks and simultaneously received treatment with DHEA (10 mg/kg by subcutaneous injection) once weekly. Body weight, retroperitoneal fat depot weight, serum glucose, insulin, and leptin levels, and hepatic lipids were measured. HFD exposure increased the adiposity index in both sexes, the hepatic triglyceride content in both sexes, and the hepatic total cholesterol level in males. Moreover, the HFD induced an increase in blood glucose levels in both sexes, and hyperinsulinemia in males. In this experimental model, DHEA treatment reduced hepatic triglyceride levels only in females, regardless of HFD exposure. Exposure to a HFD, even if it does not cause obesity, may enhance risk factors for metabolic disorders, and males are more sensitive to this effect. DHEA treatment can help prevent metabolic derangements, but its effect varies with sex.
- Published
- 2015
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27. Visceral adiposity influences glucose and glycogen metabolism in control and hyperlipidic-fed animals.
- Author
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Kaiser de Souza D, de Souza FA, de Fraga LS, Peres Konrad S, Belló-Klein A, Martins da Silva RS, and Kucharski LC
- Subjects
- Animals, Body Composition physiology, Cluster Analysis, Diet, Eating physiology, Insulin Resistance physiology, Liver metabolism, Male, Muscle, Skeletal metabolism, Rats, Rats, Wistar, Adiposity physiology, Dietary Fats pharmacology, Glucose metabolism, Glycogen metabolism, Hyperlipidemias metabolism
- Abstract
Introduction: Evidences suggest that fat intake, visceral obesity and intracellular lipids are related to insulin impairment., Objective: The objective of the present paper was correlate visceral obesity and metabolic alterations in control (CTR) and hyperlipidic cafeteria diet (CFT) fed animals., Methods: After 6 months of diet treatment, liver and muscle of the male rats were utilized to determined glucose uptake and glycogen metabolism after administration of 0.4I U/kg insulin in vivo, and correlate the visceral adiposity to these two parameters., Results: Ample range of physiologic answers to body composition in metabolic profile of the both diets was found. No differences were found in glycemia and triacylglycerol after insulin action in both groups, however CFT group accumulated higher adiposity, mostly visceral fat, and showed lower glycogen content in the liver. We also found an inverse correlation between visceral adiposity and glucose uptake and a decrease of the glycogen synthase active form in the liver. CTR animals demonstrated an inverse correlation between glucose uptake and visceral adiposity in the muscle., Discussion and Conclusion: It was observed a variability of metabolic alterations in animals which can be related to degree of accumulation of abdominal adiposity and ingestion of diet fats. Further studies will be required to clarify the reasons for the observed liver alterations in CFT and muscle alterations in CTR animals., (Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.)
- Published
- 2013
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28. Effect of starvation and refeeding on amino acid metabolism in muscle of crab Neohelice granulata previously fed protein- or carbohydrate-rich diets.
- Author
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Pellegrino R, Martins TL, Pinto CB, Schein V, Kucharski LC, and Da Silva RS
- Subjects
- Aminoisobutyric Acids metabolism, Animals, Biological Transport, Brachyura physiology, Carbon metabolism, Carbon Dioxide metabolism, Carbon Radioisotopes metabolism, Enzyme Activation, Leucine metabolism, Lipid Metabolism, Male, Muscles physiology, Protein Biosynthesis, Sodium-Potassium-Exchanging ATPase metabolism, Time Factors, Brachyura metabolism, Dietary Carbohydrates metabolism, Dietary Proteins metabolism, Food Deprivation, Glycine metabolism, Muscles metabolism
- Abstract
The present study assesses the effects of starvation and refeeding on 1-[(14)C]-methyl aminoisobutyric acid ((14)C-MeAIB) uptake, (14)C-total lipids, (14)CO(2) production from (14)C-glycine, (14)C-protein synthesis from (14)C-leucine and Na(+)-K(+)-ATPase activity in jaw muscle of Neohelice granulata previously maintained on a carbohydrate-rich (HC) or high-protein (HP) diet. In N. granulata the metabolic adjustments during starvation and refeeding use different pathways according to the composition of the diet previously offered to the crabs. During starvation, (14)CO(2) production from (14)C-glycine, and (14)C-protein synthesis from (14)C-leucine were reduced in HC-fed crabs. In crabs maintained on the HP or HC diet, (14)C-total lipid synthesis increased after 15 days of starvation. In crabs fed HP diet, (14)C-MeAIB uptake and Na(+)-K(+)-ATPase activity decreased in refeeding state. In crabs refeeding HC diet, (14)C-MeAIB uptake and (14)CO(2) production decreased during the refeeding. In contrast, the (14)C-protein synthesis increased after 120h of refeeding. In both dietary groups, (14)C-total lipid synthesis increased during refeeding. Changes in the carbon amino acid flux between different metabolic pathways in muscle are among the strategies used by this crab to face starvation and refeeding. Protein or carbohydrate levels in the diet administered to this crab modulate the carbon flux between the different metabolic pathways., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2013
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29. The activity of mate saponins (Ilex paraguariensis) in intra-abdominal and epididymal fat, and glucose oxidation in male Wistar rats.
- Author
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Resende PE, Verza SG, Kaiser S, Gomes LF, Kucharski LC, and Ortega GG
- Subjects
- Adipose Tissue growth & development, Adipose Tissue metabolism, Animals, Epididymis, Fruit, Liver drug effects, Liver metabolism, Male, Oxidation-Reduction, Plant Leaves, Rats, Rats, Wistar, Triglycerides blood, Adipose Tissue drug effects, Glucose metabolism, Ilex paraguariensis, Plant Extracts pharmacology, Saponins pharmacology
- Abstract
Ethnopharmacological Relevance: Ilex paraguariensis A. St. Hilaire (mate) has traditionally been used in several South American countries to prepare tea-like beverages having stimulant effects on the CNS and appetite. In recent years, however, mate preparations have been recommended putatively as an appetite suppressant and slimming remedy. Moreover, studies carried out on either normal or diet-induced obese rats treated with mate extracts revealed anti-obesity and satiety effects, thus refuting ethnopharmacological data. In this work, the effect of mate on the intra-abdominal and epididymal fat, and glucose oxidation levels after oral administration in male Wistar rats, was studied using crude extract from leaves, unripe fruits, and a chemically well-defined purified saponin fraction (MSF)., Material and Methods: Saponin, polyphenol and methylxanthine contents in MSF were analyzed by HPLC-PDA and UPLC/Q-TOF-MS. Crude extracts from mate leaves (LAE) and unripe fruits (FHE) were assayed for comparison purposes. Male Wistar rats fed with standard diet and water ad libitum were used as the control group., Results: The fat weight and both liver and adipose glucose oxidation were reduced significantly by MSF (35, 90 and 60%, respectively), while LAE and FHE were less active. Also, a significant lowering of the blood triglycerides level was observed in rats treated with MSF and LAE. All creatinine, urea, and transaminase plasma levels remained unaffected no matter what mate preparation was considered. It is also worth pointing out that the glucose blood level was increased after treatment with FHE. This finding did not correlate either with the content of methylxanthines, polyphenols or saponins., Conclusion: A reduction in both visceral fat weight and glucose oxidation of hepatic and adipose tissue in healthy rats fed with a standard diet could be ascribed to a purified mate saponin fraction from unripe fruits. These findings agree with former studies carried out with crude mate extracts and also suggest their potential use as an anti-obesity preparation. Nonetheless, further in vivo experiments are still required to corroborate its effect on human beings., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
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30. Estrus cycle effect on muscle tyrosine kinase activity in bitches.
- Author
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Gomes Pöppl Á, Costa Valle S, Hilário Díaz González F, de Castro Beck CA, Kucharski LC, and Silveira Martins Da Silva R
- Subjects
- Animals, Female, Dogs metabolism, Estrous Cycle, Muscle, Skeletal enzymology, Receptor Protein-Tyrosine Kinases metabolism
- Abstract
Estrus cycle is a well recognized cause of insulin resistance in bitches. The insulin receptor (IR) as well as the insulin-like growth factor-I receptor belong to the same subfamily of tyrosine kinase (TK) receptors. The objective of this study was to evaluate basal TK activity in muscle tissue of bitches during the estrus cycle. Twenty-four bitches were used in the study (7 in anestrus, 7 in estrus, and 10 in diestrus). Muscle samples, taken after spaying surgery to determine TK activity, were immediately frozen in liquid nitrogen and then stored at -80°C until the membranes were prepared by sequential centrifugation after being homogenized. TK activity was determined by Poly (Glu 4:Tyr 1) phosphorylation and expressed in cpm/μg of protein. TK activity was significantly lower (P < 0.001) in the animals in estrus (104.5 ± 11.9 cpm/μg of protein) and diestrus (94.5 ± 16.9 cpm/μg of protein) when compared with bitches in anestrus (183.2 ± 39.2 cpm/μg of protein). These results demonstrate, for the first time, lower basal TK activity in the muscle tissue of female dogs during estrus and diestrus, which may represent lower insulin signaling capacity, opening a new field of investigation into the molecular mechanisms of insulin resistance in dogs.
- Published
- 2012
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31. Effects of dehydroepiandrosterone (DHEA) and lactate on glucose uptake in the central nervous system.
- Author
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de Souza DK, Ribeiro MF, and Kucharski LC
- Subjects
- Adjuvants, Immunologic pharmacology, Animals, Male, Rats, Rats, Wistar, Tissue Distribution, Brain drug effects, Brain metabolism, Dehydroepiandrosterone pharmacology, Glucose metabolism, Lactic Acid metabolism
- Abstract
Dehydroepiandrosterone (DHEA) prevents brain aging, enhances the cerebral metabolism and interacts with energy substrates. The interaction between lactate and DHEA on glucose uptake and lactate oxidation by various nervous structures was investigated and results demonstrate that the 2-(14)C-deoxiglucose (2-(14)C-Dglucose) uptake was stimulated by 10mM lactate in the hypothalamus and olfactory bulb, inhibited in the cerebral cortex and cerebellum, and unaffected in the hippocampus. We also show that, in both the cerebral cortex and hypothalamus, (14)C-lactate oxidation was higher than (14)C-glucose oxidation (p≤0.001), demonstrating a relevant role for lactate as energy substrate. The interaction of lactate and 10(-8)M DHEA was tested and, although DHEA had no significant effect on uptake in the cerebellum, hippocampus, or hypothalamus, 10(-8)M DHEA increased the 2-(14)C-Dglucose uptake in the cerebral cortex in the presence of lactate (p≤0.001), and in the olfactory bulb in the absence of lactate (p<0.05). However, DHEA had no significant effect on (14)C-lactate oxidation. We suggest that DHEA improves glucose uptake in specific conditions. Thus, DHEA may affect CNS metabolism and interact with lactate, which is the most important neuronal energy substrate, on glucose uptake., (Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
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32. Dehydroepiandrosterone improves hepatic antioxidant reserve and stimulates Akt signaling in young and old rats.
- Author
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Jacob MH, Janner Dda R, Araújo AS, Jahn MP, Kucharski LC, Moraes TB, Dutra Filho CS, Ribeiro MF, and Belló-Klein A
- Subjects
- Age Factors, Animals, Blotting, Western, Catalase metabolism, Glucosephosphate Dehydrogenase metabolism, Glutathione metabolism, Glutathione Peroxidase metabolism, Glutathione Transferase metabolism, Hydrogen Peroxide metabolism, Liver enzymology, Male, Rats, Rats, Wistar, Antioxidants metabolism, Dehydroepiandrosterone pharmacology, Liver metabolism, Proto-Oncogene Proteins c-akt metabolism, Signal Transduction drug effects
- Abstract
This study examined, in the liver of young and old (3- and 24-month-old, respectively) healthy Wistar rats, the in vivo effect of dehydroepiandrosterone (DHEA) (10mg/kg body weight) administered subcutaneously for 5 weeks. Reduced (GSH) and oxidized (GSSG) glutathione levels, glucose-6-phosphate dehydrogenase (G6PDH), glutathione-S-transferase (GST), glutathione peroxidase (GPx) and catalase (CAT) activities, hydrogen peroxide concentration, GST and p-Akt/Akt immunocontent ratio were assessed in hepatic tissue. DHEA treatment significantly increased total glutathione content (17%) and GSH (22%) in 3- and 24-month-old treated groups when compared to control groups. The aging factor increased G6PDH (51%) and GPx (22%) activities as well as the hydrogen peroxide concentration (33%), independently of treatment. DHEA treatment increased p-Akt (54%) and p-Akt/Akt ratio (36%) immunocontents in both treated groups. Increased serum levels of alanine aminotransferase (ALT) in aged rats were reduced by DHEA treatment (34%)., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
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33. Effects of angiotensin-I and ischemia on functional recovery in isolated hearts.
- Author
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Oliveira UO, Oliveira AR, Kucharski LC, Machado UF, Irigoyen MC, and Schaan BD
- Subjects
- Analysis of Variance, Angiotensin-Converting Enzyme Inhibitors pharmacology, Animals, Captopril pharmacology, Male, Models, Animal, Myocardial Ischemia physiopathology, Myocardial Reperfusion Injury prevention & control, Random Allocation, Rats, Rats, Wistar, Time Factors, Angiotensin I pharmacology, Myocardial Ischemia drug therapy, Myocardial Reperfusion methods, Recovery of Function drug effects
- Abstract
Background: Cardiac arrest resuscitation can present myocardial dysfunction determined by ischemic time, and inhibition of the angiotensin-converting enzyme (ACE) can reduce cardiac dysfunction during reperfusion., Objective: To investigate the effects of angiotensin-I and different periods of ischemia on functional recovery in isolated rat hearts., Methods: Isolated hearts from Wistar rats (n=45; 250-300 g) were submitted to different periods of global ischemia (20, 25 or 30 min) and reperfused (30 min) with Krebs-Henseleit buffer alone or with the addition of 400 nmol/L angiotensin-I, or 400 nmol/L angiotensin-I + 100 μmol/L captopril along the reperfusion period., Results: The maximal positive derivative of pressure (+dP/dt(max)) and rate-pressure product were reduced in hearts exposed to 25 min ischemia (~73%) and 30 min ischemia (~80%) vs. 20 min ischemia. Left ventricular end-diastolic pressure (LVEDP) and perfusion pressure (PP) were increased in hearts exposed to 25 min ischemia (5.5 and 1.08 fold, respectively) and 30 min ischemia (6 and 1.10 fold, respectively) vs. 20 min ischemia. Angiotensin-I caused a decrease in +dP/dt(max) and rate-pressure product (~85-94%) in all ischemic periods and an increase in LVEDP and PP (6.9 and 1.25 fold, respectively) only at 20 min ischemia. Captopril was able to partially or completely reverse the effects of angiotensin-I on functional recovery in 20 min and 25 min ischemia., Conclusion: These data suggest that angiotensin-II directly or indirectly participates in the post-ischemic damage, and the ability of an ACE inhibitor to attenuate this damage depends on ischemic time.
- Published
- 2011
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34. The effect of aqueous extract of gross and commercial yerba mate (Ilex paraguariensis) on intra-abdominal and epididymal fat and glucose levels in male Wistar rats.
- Author
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Silva RD, Bueno AL, Gallon CW, Gomes LF, Kaiser S, Pavei C, Ortega GG, Kucharski LC, and Jahn MP
- Subjects
- Adipose Tissue metabolism, Animals, Blood Glucose metabolism, Body Weight drug effects, Epididymis metabolism, Intra-Abdominal Fat drug effects, Male, Plant Components, Aerial chemistry, Plant Extracts chemistry, Plant Extracts pharmacology, Polyphenols chemistry, Polyphenols isolation & purification, Random Allocation, Rats, Rats, Wistar, Saponins chemistry, Saponins isolation & purification, Xanthines chemistry, Xanthines isolation & purification, Adipose Tissue drug effects, Blood Glucose drug effects, Ilex paraguariensis chemistry, Polyphenols pharmacology, Saponins pharmacology, Xanthines pharmacology
- Abstract
This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
- Full Text
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35. The effect of dehydroepiandrosterone (DHEA) on renal function and metabolism in diabetic rats.
- Author
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Jahn MP, Gomes LF, Jacob MH, da Rocha Janner D, Araújo AS, Belló-Klein A, Ribeiro MF, and Kucharski LC
- Subjects
- Animals, Blood Glucose drug effects, Body Weight drug effects, Creatinine blood, Diabetes Mellitus, Experimental physiopathology, Glucose metabolism, Glutathione metabolism, Kidney metabolism, Male, Organ Size drug effects, Oxidation-Reduction, Rats, Rats, Wistar, Transforming Growth Factor beta1 urine, Dehydroepiandrosterone pharmacology, Diabetes Mellitus, Experimental metabolism, Glomerular Filtration Rate drug effects, Kidney drug effects
- Abstract
Dehydroepiandrosterone (DHEA) is an endogenous steroid hormone involved in a number of biological actions in humans and rodents, but its effects on renal tissue have not yet been fully understood. The aim of this study is to assess the effect of DHEA treatment on diabetic rats, mainly in relation to renal function and metabolism. Diabetic rats were treated with subcutaneous injections of a 10mg/kg dose of DHEA diluted in oil. Plasma glucose and creatinine, in addition to urine creatinine, were quantified espectophotometrically. Glucose uptake and oxidation were quantified using radioactive glucose, the urinary Transforming Growth Factor β(1) (TGF-β(1)) was assessed by enzyme immunoassay, and the total glutathione in the renal tissue was also measured. The diabetic rats displayed higher levels of glycemia, and DHEA treatment reduced hyperglycemia. Plasmatic creatinine levels were higher in the diabetic rats treated with DHEA, while creatinine clearance was lower. Glucose uptake and oxidation were lower in the renal medulla of the diabetic rats treated with DHEA, and urinary TGF-β(1), as well as total gluthatione levels, were higher in the diabetic rats treated with DHEA. DHEA treatment was not beneficial to renal tissue, since it reduced the glomerular filtration rate and renal medulla metabolism, while increasing the urinary excretion of TGF-β(1) and the compensatory response by the glutathione system, probably due to a mechanism involving a pro-oxidant action or a pro-fibrotic effect of this androgen or its derivatives. In conclusion, this study reports that DHEA treatment may be harmful to renal tissue, but the mechanisms of this action have not yet been fully understood., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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36. Effects of hypo- or hyperosmotic stress on lipid synthesis and gluconeogenic activity in tissues of the crab Neohelice granulata.
- Author
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Martins TL, Chittó AL, Rossetti CL, Brondani CK, Kucharski LC, and Da Silva RS
- Subjects
- Animals, Carboxy-Lyases metabolism, Fructose-Bisphosphatase metabolism, Gills enzymology, Glucose-6-Phosphatase metabolism, Hepatopancreas enzymology, Male, Muscles enzymology, Osmotic Pressure, Brachyura enzymology, Gluconeogenesis, Lipids biosynthesis
- Abstract
The present study assesses the effects of osmotic stress on phosphoenolpyruvate carboxykinase (PEPCK), fructose 1,6-bisphosphatase (FBPase) and glucose 6-phosphatase (G6Pase) activities and (14)C-total lipid synthesis from (14)C-glycine in the anterior and posterior gills, jaw muscle, and hepatopancreas of Neohelice granulata. In posterior gills, 24-h exposure to hyperosmotic stress increased PEPCK, FBPase and G6Pase activities. Increase in (14)C-lipid synthesis was associated to the decrease in PEPCK activity after 72-h exposure to hyperosmotic stress. Hypo-osmotic stress decreased PEPCK and G6Pase activities in posterior gills; however, (14)C-lipids increased after 72-h exposure to stress. In anterior gills, decreases in the G6Pase activity after 72-h of hyperosmotic stress and in (14)C-lipogenesis after 144-h were observed, while PEPCK activity increased after 144 h. Exposure to hypo-osmotic stress increased (14)C-lipid synthesis and PEPCK activity in anterior gills. Muscle G6Pase activity increased after 72-h exposure to hypo-osmotic stress; however, no significant change was observed in the lipogenesis. PEPCK decreased in muscle after 144-h exposure to hyperosmotic, coinciding with increased (14)C-lipid synthesis. In the hepatopancreas, a decrease in the (14)C-lipogenesis occurred after 24-h exposure to hyperosmotic stress, accompanied by increase in (14)C-lipid synthesis. Additionally, PEPCK activity returned to control levels. The hepatopancreatic lipogenesis from amino acids was not involved in the metabolic adjustment during hypo-osmotic stress. However, gluconeogenesis is one of the pathways involved in the adjustment of the intracellular concentration of nitrogenated compounds., (Copyright © 2010. Published by Elsevier Inc.)
- Published
- 2011
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37. Redox imbalance influence in the myocardial Akt activation in aged rats treated with DHEA.
- Author
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Jacob MH, Janner Dda R, Araújo AS, Jahn MP, Kucharski LC, Moraes TB, Dutra Filho CS, Ribeiro MF, and Belló-Klein A
- Subjects
- Animals, Glutathione Disulfide metabolism, Glutathione Peroxidase metabolism, Glutathione Transferase metabolism, Heart drug effects, Male, Models, Animal, NF-E2-Related Factor 2 metabolism, Oxidation-Reduction drug effects, Rats, Rats, Wistar, Aging metabolism, Dehydroepiandrosterone pharmacology, Myocardium metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
This study examined, in young and old (3 and 24 month-old, respectively) healthy Wistar rats, the in vivo effect of DHEA (10 mg/kg body weight) administered subcutaneously for 5 weeks. Reduced (GSH) and oxidized (GSSG) glutathione levels, glucose-6-phosphate dehydrogenase (G6PDH), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and thioredoxin (Trx) reductase activities, hydrogen peroxide steady-state concentration and Nrf2, GST, Trx-1, Akt and p-Akt expressions were assessed in heart tissue. DHEA treatment significantly increased GST activity in 3 and 24 month-old treated groups. The aging factor diminished hydrogen peroxide concentration and Nrf2 expression, independently of treatment. However, the aging process increased GST, Akt and p-Akt expressions in both 24 month-old groups. The aged group responded differently to DHEA respective to GSSG content, GPx activity and p-Akt concentration. Further studies are needed to form conclusions about the efficacy and safety of DHEA replacement in the elderly, and to better understand DHEA's net effect on oxidative stress parameters and its modulation of signaling cascades., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
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38. Dehydroepiandrosterone effects on Akt signaling modulation in central nervous system of young and aged healthy rats.
- Author
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Janner Dda R, Jacob MH, Jahn MP, Kucharski LC, and Ribeiro MF
- Subjects
- Adjuvants, Immunologic administration & dosage, Aging drug effects, Animals, Dehydroepiandrosterone administration & dosage, Male, Rats, Rats, Wistar, Signal Transduction drug effects, Adjuvants, Immunologic pharmacology, Dehydroepiandrosterone pharmacology, Hippocampus drug effects, Hypothalamus drug effects, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Dehydroepiandrosterone (DHEA) is a steroid synthesized in adrenal cortex as well as in the nervous system. DHEA effects on central nervous system (CNS) have been associated with several brain functions such as marked neurotrophic and neuroprotective activity. DHEA plasma concentration decreases steadily with aging and studies have reported an inverse correlation between levels of DHEA and neurological diseases age-associated. Nonetheless, its mechanisms of action are not yet fully understood. Akt signaling pathway is one protein kinase which has been related to be DHEA modulated. The goal of this study was to investigate whether short-term (6 or 24h) or chronic (5 weeks) DHEA treatment modulates Akt in CNS of adult (3 months) and aged (18 and 24 months) healthy rats. Hypothalamus and hippocampus homogenates were prepared to quantify total-Akt and phosphorylated Akt at Ser(473) (pAkt). The results here presented have shown that acute (50mg/kg) and chronic (10mg/kg) DHEA injections modulate total and pAkt levels. This effect was dose and time-dependent as well as age and tissue-dependent. In addition, the age variable also intervenes on total and pAkt levels expression independently of DHEA treatment., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
39. The effect of long-term DHEA treatment on glucose metabolism, hydrogen peroxide and thioredoxin levels in the skeletal muscle of diabetic rats.
- Author
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Jahn MP, Jacob MH, Gomes LF, Duarte R, Araújo AS, Belló-Klein A, Ribeiro MF, and Kucharski LC
- Subjects
- Animals, Blood Glucose metabolism, Male, Oxidation-Reduction drug effects, Rats, Rats, Wistar, Time Factors, Dehydroepiandrosterone pharmacology, Diabetes Mellitus, Experimental metabolism, Glucose metabolism, Hydrogen Peroxide metabolism, Muscle, Skeletal drug effects, Thioredoxins metabolism
- Abstract
Dehydroepiandrosterone (DHEA) is an endogenous steroid hormone involved in a number of biological actions. This study shows the effects of DHEA on glucose metabolism, hydrogen peroxide and thioredoxin levels in the skeletal muscle of control and diabetic rats. Control and diabetic rats were chronically treated with DHEA (10mg/kg) diluted in oil. Plasma concentration of DHEA and glucose, glucose uptake and oxidation, hydrogen peroxide, GLUT4, Akt and thioredoxin (Trx) was measured in the muscle. Results showed that there was a decrease in blood glucose in diabetic rats, probably linked to an increase in the glucose oxidation by the muscle or glucose uptake by some tissues. Despite the increase in the expression of GLUT4 in DHEA-treated rats, the glucose uptake was only higher in the control rats, showing that the glucose transporter may be present but not functional in the diabetic rats. The low expression of Trx due to diabetes became even lower with DHEA treatment. Although the reduction in blood glucose may be favorable, the decrease in Akt and Trx displays an environment conducive to redox imbalance. Thus, further studies are needed to ascertain the effects of DHEA treatment in diabetic rats.
- Published
- 2010
- Full Text
- View/download PDF
40. Increased resistance to hydrogen peroxide-induced cardiac contracture is associated with decreased myocardial oxidative stress in hypothyroid rats.
- Author
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da Rosa Araujo AS, Silva de Miranda MF, de Oliveira UO, Fernandes T, Llesuy S, Rios Kucharski LC, Khaper N, and Belló-Klein A
- Subjects
- Animals, Catalase metabolism, Contracture chemically induced, Disease Models, Animal, Glutathione Peroxidase metabolism, Lipid Peroxidation, Male, Protein Carbonylation, Rats, Rats, Wistar, Superoxide Dismutase metabolism, Thiobarbituric Acid Reactive Substances metabolism, Contracture metabolism, Hydrogen Peroxide pharmacology, Hypothyroidism metabolism, Myocardium metabolism, Oxidative Stress drug effects
- Abstract
The purpose of this study was to determine whether decreased oxidative stress would increase the resistance to cardiac contracture induced by H(2)O(2) in hypothyroid rats. Male Wistar rats were divided into two groups: control and hypothyroid. Hypothyroidism was induced via thyroidectomy. Four weeks post surgery, blood samples were collected to perform thyroid hormone assessments, and excised hearts were perfused at a constant flow with or without H(2)O(2) (1 mmol/L), being divided into two sub-groups: control, hypothyroid, control + H(2)O(2), hypothyroid + H(2)O(2). Lipid peroxidation (LPO) was evaluated by chemiluminescence (CL) and thiobarbituric acid reactive substances (TBARS) methods, and protein oxidation by carbonyls assay in heart homogenates. Cardiac tissue was also screened for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, and for total radical-trapping antioxidant potential (TRAP). Analyses of SOD and glutathione-S-transferase (GST) protein expression were also performed in heart homogenates. Hypothyroid hearts were found to be more resistant to H(2)O(2)-induced contracture (60% elevation in LVEDP) as compared to control. CL, TBARS, carbonyl, as well as SOD, CAT, GPx activities and TRAP levels were reduced (35, 30, 40, 30, 16, 25, and 33%, respectively) in the cardiac homogenates of the hypothyroid group as compared to controls. A decrease in SOD and GST protein levels by 20 and 16%, respectively, was also observed in the hypothyroid group. These results suggest that a hypometabolic state caused by thyroid hormone deficiency can lead to an improved response to H(2)O(2) challenge and is associated with decreased oxidative myocardial damage., (2009 John Wiley & Sons, Ltd.)
- Published
- 2010
- Full Text
- View/download PDF
41. Age-related effects of DHEA on peripheral markers of oxidative stress.
- Author
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Jacob MH, da R Janner D, Jahn MP, Kucharski LC, Belló-Klein A, and Ribeiro MF
- Subjects
- Age Factors, Animals, Catalase metabolism, Erythrocytes metabolism, Glutathione Transferase metabolism, Lipid Peroxidation, Male, Rats, Rats, Wistar, Superoxide Dismutase metabolism, Aging, Dehydroepiandrosterone pharmacology, Oxidative Stress drug effects
- Abstract
Ageing is an inevitable biological process characterized by a general decline in various physiological functions. DHEA and DHEAS levels are maximal between the second and third life decades, then start to decline 2% per year, leaving a residual of 10-20% of the peak production by the eighth decade. Erythrocytes are exposed to frequent oxidative stress due to the oxygen radicals continuously generated by haemoglobin auto-oxidation. We investigated DHEA chronic (10 mg/kg, subcutaneously, for 5 weeks) effects over oxidative stress markers in erythrocytes of male Wistar rats of 3, 13 and 18 month-old. In the 13 month-old group, we found increased lipid peroxidation (LPO), superoxide dismutase (SOD), glutathione-S-transferase and catalase activities when compared to the other age groups. DHEA produced a marked increase in LPO of 13 month-old group when compared to its control. DHEA exerted this pro-oxidant effects in all ages studied, especially in age 13 month-old. It seems that at 13 month-old there would be an important depletion of some specific anti-oxidant in order to determine such susceptibility to DHEA effects. Since this approach allows a minimally invasive assessment, it would be useful as a routine method in human clinical studies investigating DHEA effects during the ageing process., (2009 John Wiley & Sons, Ltd.)
- Published
- 2010
- Full Text
- View/download PDF
42. DHEA effects on myocardial Akt signaling modulation and oxidative stress changes in aged rats.
- Author
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Jacob MH, Janner Dda R, Jahn MP, Kucharski LC, Belló-Klein A, and Ribeiro MF
- Subjects
- Aging drug effects, Aging physiology, Animals, Glutathione Transferase drug effects, Glutathione Transferase metabolism, Lipid Peroxidation drug effects, Lipid Peroxidation physiology, Male, Oxidative Stress physiology, Proto-Oncogene Proteins c-akt agonists, Rats, Rats, Wistar, Signal Transduction drug effects, Signal Transduction physiology, Superoxide Dismutase antagonists & inhibitors, Dehydroepiandrosterone pharmacology, Heart drug effects, Myocardium enzymology, Oxidative Stress drug effects, Proto-Oncogene Proteins c-akt metabolism, Superoxide Dismutase metabolism
- Abstract
The secretion of DHEA-synthesized mainly in the adrenal cortex-increases in the postnatal aging, peaks in the twenties and decreases with age afterwards. Exogenous DHEA can exert a dual effect depending on dose and on tissue. Akt is a serine/threonine kinase whose activity has been seen as an interventional approach for cardiomyopathic damage resulting from aging changes. In order to evaluate DHEA effects over myocardial Akt protein expression associated to oxidative stress markers during aging, male Wistar rats (3 and 18 months) were assigned into two groups: control or DHEA (10mg/kg, subcutaneously, for 5 weeks). In the aged group, we found increased lipid peroxidation and glutathione-S-transferase activity. DHEA produced an increase in p-Akt protein expression and a decrease in SOD activity in both ages. Akt pathway activation might be related to changes in oxidative stress parameters according to age.
- Published
- 2009
- Full Text
- View/download PDF
43. Seasonal variation in glucose and neutral amino acid uptake in the estuarine crab Neohelice granulata.
- Author
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Valle SC, Eichler P, Maciel JE, Machado G, Kucharski LC, and Da Silva RS
- Subjects
- Amino Acids chemistry, Animals, Brachyura chemistry, Gills chemistry, Gills metabolism, Glucose analogs & derivatives, Glucose chemistry, Hydrogen-Ion Concentration, Masseter Muscle chemistry, Masseter Muscle metabolism, Water chemistry, Water physiology, Amino Acids metabolism, Brachyura metabolism, Glucose metabolism, Seasons
- Abstract
This study investigates the mechanisms of glucose and amino acid transport in gills and jaw muscle of N. granulata collected from an estuarine natural population. The physicochemical parameters of the estuarine environment and of this crustacean's hemolymph were measured during different seasons of the year. In summer, the lagoon water osmolality increased (5-6 times), and hemolymph osmolality decreased. In fall, water pH increased, whereas hemolymph pH decreased markedly. In all seasons, 2-deoxi glucose (DG) uptake in gills was significantly higher than 3-O methyl-glucose (MG) uptake. Phloretin reduced DG uptake in gills; phloretin and phlorizin did not affect MG uptake in this organ. DG and MG uptake was highest in gills during spring and summer. In jaw muscle, MG uptake in winter and spring was higher than DG uptake. In fall, gill methyl aminoisobutyric acid (MeAIB) uptake increased. In jaw muscle, MeAIB uptake was higher in spring. The observed changes in glucose uptake and in the type of glucose and amino acid transporter used in gills and muscle appear to be strategies used by N. granulata to minimize seasonal oscillations in the environmental parameters of their estuarine habitat.
- Published
- 2009
- Full Text
- View/download PDF
44. On the reliability of a simple method for scoring phenotypes to estimate heritability: A case study with pupal color in Heliconius erato phyllis, Fabricius 1775 (Lepidoptera, Nymphalidae).
- Author
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Ferreira AA, Kucharski LC, and de Araújo AM
- Abstract
In this paper, two methods for assessing the degree of melanization of pupal exuviae from the butterfly Heliconius erato phyllis, Fabricius 1775 (Lepidoptera, Nymphalidae, Heliconiini) are compared. In the first method, which was qualitative, the exuviae were classified by scoring the degree of melanization, whereas in the second method, which was quantitative, the exuviae were classified by optical density followed by analysis with appropriate software. The heritability (h(2)) of the degree of melanization was estimated by regression and analysis of variance. The estimates of h (2) were similar with both methods, indicating that the qualitative method could be particularly suitable for field work. The low estimates obtained for heritability may have resulted from the small sample size (n = 7-18 broods, including the parents) or from the allocation-priority hypothesis in which pupal color would be a lower priority trait compared to morphological traits and adequate larval development.
- Published
- 2009
- Full Text
- View/download PDF
45. Lactate metabolism in the muscle of the crab Chasmagnathus granulatus during hypoxia and post-hypoxia recovery.
- Author
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Maciel JE, Souza F, Valle S, Kucharski LC, and da Silva RS
- Subjects
- Anaerobiosis, Animals, Blood Glucose metabolism, Carbon Isotopes, Gluconeogenesis, Glycogen metabolism, Hemolymph metabolism, Jaw metabolism, Lactic Acid blood, Male, Oxidation-Reduction, Brachyura metabolism, Lactic Acid metabolism, Muscles metabolism
- Abstract
The present study showed that the lactate/glucose ratio in the hemolymph of Chasmagnathus granulatus maintained in normoxia (controls) was 4.9, suggesting that lactate is an important substrate for this crab. Periods of hypoxia are part of the biological cycle of this crab, and lactate is the main end product of anaerobiosis in this crab. Our hypothesis was that this lactate would be, therefore, used by gluconeogenic pathway or can be oxidized or excreted to the aquatic medium during hypoxia and post-hypoxia periods in C. granulatus. The concentrations of hemolymphatic lactate in animals in normoxia are high, and are used as an energy substrate. In hypoxia, muscle gluconeogenesis and excretion of lactate to the aquatic medium would contribute significantly in regulating the concentration of circulating lactate. Utilization of these pathways would serve the objective of maintaining the acid-base equilibrium of the organism. Muscle gluconeogenesis participates, during the recovery process, in metabolizing the lactate produced during the period of hypoxia. Lactate excretion to the external medium, was one of the strategies used to decrease the higher hemolymphatic lactate levels. However, oxidation of lactate in the muscle is not a main strategy used by this crab to metabolize lactate in the recovery periods.
- Published
- 2008
- Full Text
- View/download PDF
46. Insulin receptor tyrosine kinase activity and substrate 1 (IRS-1) expression in human myometrium and leiomyoma.
- Author
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Orcy RB, Brum I, da Silva RS, Kucharski LC, Corleta Hv, and Capp E
- Subjects
- Animals, Female, Humans, In Vitro Techniques, Insulin pharmacology, Insulin Receptor Substrate Proteins, Muscle, Skeletal metabolism, Myometrium drug effects, Phosphorylation, Rats, Rats, Wistar, Reference Values, Leiomyoma metabolism, Myometrium metabolism, Phosphoproteins metabolism, Protein-Tyrosine Kinases metabolism, Uterine Neoplasms metabolism
- Abstract
Background: Uterine leiomyomas are the commonest tumors of the genital tract. Growth factors seem to be implicated in the development of leiomyoma., Objective: To determine the insulin receptor (IR) tyrosine kinase activity--phosphorylation of exogenous substrate poly(Glu 4: Tyr 1)--and insulin receptor substrate 1 expression in normal myometrium and leiomyoma., Study Design: The study group consisted of 12 women with leiomyoma undergoing routine hysterectomy. Samples of leiomyoma and adjacent normal myometrium were obtained at the time of operation. Plasma membrane fractions were prepared and samples were incubated with and without insulin and incubated with exogenous substrate poly(Glu 4: Tyr 1). IRS-1 expression was studied in the whole lysate via Western blotting using specific antibodies. Data were analyzed using Student's t-test., Results: The phosphorylation of the exogenous substrate poly(Glu 4: Tyr 1) in myometrium (1.566+/-0.177) and in leiomyoma (1.98+/-0.612) were similar (P=0.774). The IRS-1 levels in myometrium (0.190+/-0.022) and in leiomyoma (0.226+/-0.022) were not different (P=0.184)., Conclusions: There was no difference in IR tyrosine kinase activity (phosphorylation of exogenous substrate) and IRS-1 expression between normal myometrium and leiomyomata. Other steps in the insulin signaling cascade require further study to investigate the role of insulin receptor in leiomyomata.
- Published
- 2005
- Full Text
- View/download PDF
47. Effect of hyper or hypo-osmotic conditions on neutral amino acid uptake and oxidation in tissues of the crab Chasmagnathus granulata.
- Author
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Schein V, Fernandes Chittó AL, Etges R, Kucharski LC, van Wormhoudt A, and Da Silva RS
- Subjects
- Alanine chemistry, Alanine metabolism, Animals, Brachyura chemistry, Brachyura metabolism, Carbon Dioxide metabolism, Carbon Isotopes, Hepatopancreas chemistry, Hepatopancreas metabolism, Jaw chemistry, Jaw metabolism, Muscles chemistry, Muscles metabolism, Osmotic Pressure, Oxidation-Reduction, Time Factors, beta-Alanine analogs & derivatives, beta-Alanine chemistry, beta-Alanine metabolism, Amino Acids chemistry, Amino Acids metabolism
- Abstract
We investigated the transport of (14)C-methylaminoisobutyric acid ((14)C-MeAIB) and (14)C-alanine oxidation in hepatopancreas and jaw muscle of Chasmagnathus granulata submitted to 24, 72, and 144 h of hypo- or hyperosmotic stress. While (14)C-MeAIB uptake increased in jaw muscle and hepatopancreas from crabs submitted to hyperosmotic stress, it did not change in tissues from animals submitted to hypo-osmotic stress. Incubation of jaw muscle and hepatopancreas from control groups with 1 mM ouabain did not decrease (14)C-MeAIB uptake. However, ouabain prevented (14)C-MeAIB uptake in hepatopancreas at 24 h of hyperosmotic stress. In contrast, in jaw muscle from crabs submitted to the same conditions, (14)C-MeAIB uptake was not prevented by ouabain in the incubation medium. Jaw muscle from the control group produced four times more (14)CO(2) from (14)C-alanine than the hepatopancreas. During hypo-osmotic stress, amino acid oxidation does not seem to be one of the pathways implicated in the decrease of the amino acid pools in hepatopancreas and jaw muscle. In contrast, during hyperosmotic stress the reduction in (14)C-alanine oxidation appears to be one of the mechanisms involved in the increase of the amino acid pool in the hepatopancreas.
- Published
- 2005
- Full Text
- View/download PDF
48. Effects of environmental anoxia and different periods of reoxygenation on oxidative balance in gills of the estuarine crab Chasmagnathus granulata.
- Author
-
de Oliveira UO, da Rosa Araújo AS, Belló-Klein A, da Silva RS, and Kucharski LC
- Subjects
- Animals, Catalase metabolism, Environmental Exposure, Glutathione Transferase metabolism, Lipid Peroxidation, Male, Reactive Oxygen Species metabolism, Superoxide Dismutase metabolism, Thiobarbituric Acid Reactive Substances metabolism, Antioxidants metabolism, Brachyura metabolism, Gills enzymology, Hypoxia metabolism, Oxidative Stress, Oxygen metabolism
- Abstract
We investigated the effects of anoxia (8 h) and different periods of reoxygenation (20 and 40 min) on the oxidative balance in anterior and posterior gills of the crab Chasmagnathus granulata. Enzyme activity of catalase and GST was increased in the gills of the animals submitted to anoxia, and SOD activity was decreased. These enzymes returned approximately to control levels during the anoxia recovery time. These results demonstrated enzyme activities change with variations in environmental oxygen levels. The posterior gills showed a higher antioxidant enzyme activity than anterior gills. In the gills, there were no changes in the non-enzymatic antioxidant system (TRAP) during anoxia. On the other hand, during anoxia recovery, an increase of TRAP in both gills was observed. Anoxia does not change lipid peroxidation (TBARS) in the gills. During anoxia recuperation, an increase in levels of TBARS was observed. Thus the results demonstrate that C. granulata has a similar strategy of preparation for oxidative stress as observed in other intertidal species, enabling the crabs to survive in an environment with extreme variations in physical and chemical characteristics, such as salt marshes.
- Published
- 2005
- Full Text
- View/download PDF
49. Effect of hyperosmotic shock on phosphoenolpyruvate carboxykinase gene expression and gluconeogenic activity in the crab muscle.
- Author
-
Schein V, Waché Y, Etges R, Kucharski LC, van Wormhoudt A, and Da Silva RS
- Subjects
- Amino Acid Sequence, Animals, Binding Sites, Brachyura, Enzyme Induction, Male, Molecular Sequence Data, Phosphoenolpyruvate Carboxykinase (GTP) biosynthesis, RNA, Messenger analysis, RNA, Messenger biosynthesis, Sequence Alignment, Sequence Analysis, DNA, Tissue Distribution, Gluconeogenesis, Muscle, Skeletal metabolism, Osmotic Pressure, Phosphoenolpyruvate Carboxykinase (GTP) genetics
- Abstract
Chasmagnathus granulata phosphoenolpyruvate carboxykinase (PEPCK) cDNA from jaw muscle was cloned and sequenced, showing a specific domain to bind phosphoenolpyruvate in addition to the kinase-1 and kinase-2 motifs to bind guanosine triphosphate (GTP) and Mg(2+), respectively, specific for all PEPCKs. In the kinase-1 motifs the GK was changed to RK. The first 19 amino acids of the putative enzyme contain hydrophobic amino acids and hydroxylated residues specific to a mitochondrial type signal. The PEPCK is expressed in hepatopancreas, muscles, nervous system, heart, and gills. Hyperosmotic stress for 24 h increased the PEPCK mRNA level, gluconeogenic and PEPCK activities in muscle.
- Published
- 2004
- Full Text
- View/download PDF
50. Hepatopancreas gluconeogenesis and glycogen content during fasting in crabs previously maintained on a high-protein or carbohydrate-rich diet.
- Author
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Oliveira GT, Rossi IC, Kucharski LC, and Da Silva RS
- Subjects
- Alanine metabolism, Animals, Carbohydrate Metabolism, Glucose analysis, Hemolymph chemistry, Lactic Acid metabolism, Male, Proteins metabolism, Brachyura metabolism, Fasting physiology, Gluconeogenesis physiology, Glycogen metabolism, Hepatopancreas metabolism
- Abstract
The present study assessed the effect of different fasting times on the in vitro gluconeogenic capacity of Chasmagnathus granulata crabs previously adapted to a high-protein (HP) or carbohydrate-rich (HC) diet using the incorporation of [U-(14)C]l-lactate or [U-(14)C]l-alanine into glucose. We also recorded haemolymphatic glucose and hepatopancreatic glycogen levels. In the HP group, on the third day of fasting there were decreases in the synthesis of glucose from (14)C-alanine and in haemolymph glucose. After 15 days of fasting, haemolymph glucose and hepatopancreatic glycogen levels were maintained by an increase in the conversion of (14)C-alanine into glucose. However, after 21 days of fasting the gluconeogenic capacity was decreased and hepatopancreas glycogen concentration was reduced. In the HC group, hepatopancreatic glycogen was the energy source during the first 6 days of fasting. Gluconeogenesis from (14)C-lactate decreased after 6 days of fasting, remaining low until 21 days of fasting. The conversion of (14)C-alanine into glucose was increased after 15 days fasting and hepatopancreatic glycogen was raised in relation to that present after a 6-day fasting. In both dietary groups the stabilization in the levels of haemolymph glucose after 21 days fasting may result from a reduction in metabolic rate during restricted feeding.
- Published
- 2004
- Full Text
- View/download PDF
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