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Urine samples of female patients with overactive bladder (OAB) are characterized by low levels of nerve growth factor (NGF) and elevated concentrations of nitric oxide (NO) compared to healthy controls. We therefore examined how NO might regulate NGF synthesis using rat bladder smooth muscle (SMCs) and urothelial (UROs) cells in culture. In UROs, incubation in hyperglycemic conditions to mimic insulin insensitivity present in the OAB cohort increased secretion of NO and concomitantly decreased NGF, except when the NO synthase inhibitor, l -NAME (1 mM) was present. Sodium nitroprusside (SNP) (300 μM, 24 h), a NO generator, decreased NGF levels and decreased cyclic GMP (cGMP) content, a process validated by the cGMP synthase inhibitor ODQ (100 μM). Alternatively, SNP increased mRNA of both NGF and matrix metalloproteinase-9 (MMP-9). MMP-9 knockout of UROs by Crispr-Cas9 potently decreased the effect of SNP on NGF, implying a dependent role of NO on MMP-9. On the other hand, matrix metalloproteinase-7 (MMP-7) activity was increased by SNP, which taken together with increase in NGF mRNA, suggests a compensatory mechanism. In SMCs, hyperglycemic conditions had the same effect on extracellular content of NO and NGF than in UROs. SNP also decreased NGF secretion but increased cGMP content. Stable permeable analogs of cGMP 8-(4-Chlorophenylthio)-cGMP (1 mM) and N2,2′-O-Dibutyryl-cGMP (3 mM) inhibited NGF release. NGF and MMP-9 mRNA expression was unchanged by SNP. Deletion of MMP-9 in SMCs by Crispr-Cas9 did not alter the effect of SNP. Finally, SNP decreased MMP-7 activity, diminishing the conversion of proNGF to NGF. These results demonstrate that enhanced NO secretion triggered by high glucose decreases NGF secretion through pathways unique for each cell type that involve cGMP and proteases MMP-7 and MMP-9. These results might help to explain our observations from the urine from patients with OAB associated with metabolic syndrome. • Hyperglycemic medium increases the release of nitric oxide by bladder cells. • Nitric oxide decreases the release of mature nerve growth factor. • Changes in cyclic GMP is required to mediate nitric oxide action. • Matrix metalloproteinases 7 and 9 are involved in neurotrophin proteolysis. [ABSTRACT FROM AUTHOR]

Metabolic syndrome is considered to be a cluster of disorders that directly contribute to the development of cardiovascular disease and are characterized by chronic systemic inflammation. Numerous epidemiological data indicate that an adverse intrauterine environment, caused by the peculiarities of the nutritional status or placental insufficiency in a woman with metabolic syndrome, can "program" the susceptibility of the fetus to further development of cardiovascular and metabolic diseases, has an impact on cognitive and behavioral development. Nitric oxide (NO) plays a critical role in the pathogenesis of components of the metabolic syndrome. Children born prematurely have a high incidence of brain damage, which can lead to motor, cognitive, behavioral, social and sensory disorders. The purpose the research was the study of the effect of the eNOS gene polymorphism and indicators of nitric oxide metabolism on the neonatal consequences in prematurely born children from mothers with metabolic syndrome. Material and methods. A study was conducted in which 100 premature infants were included. Two groups were formed: the main group (n=34), which included preterm infants (birth weight 2145.29±148.19 g and gestational age 33.18±0.55 weeks) of mothers with metabolic syndrome, and the comparison group (n=66), which included preterm infants (birth weight 2295.99±101.45 and gestational age 34.03±0.45 weeks) of mothers without metabolic syndrome. The children underwent a genetic study - determination of the polymorphism of the eNOS gene, as well as the level of nitrites, nitrates and nitrosothiols in the urine. By decision of the bioethics commission No. 217 dated 12.06.2023, the materials of the scientific work comply with the Rules of Humane Treatment of Patients. Traditional methods of parametric and nonparametric statistics were used; nonparametric methods were used to analyze qualitative characteristics expressed mainly in percentages. The methods of parametric statistics were used to check the normality of the distribution of quantitative characteristics using the Kolmogorov-Smirnov criterion. Statistical processing of the obtained results was carried out using the package of application programs EXCEL-2003® and STATA version 11 for Windows (StataCorp, Texas, USA). The work was carried out as part of the scientific and experimental work of the Department of Pediatrics #1 with Neonatology of the Poltava State Medical University "To develop clinical and laboratory criteria, methods of predicting and preventing metabolic disoders in young children (state registration number 0120U102856). Results. The most common diseases in the infants of the studied groups were the consequences of intrauterine hypoxia (44.1%) and respiratory failure requiring artificial lung ventilation (50.0%), although no significant differences were found in the prevalence of these conditions. We identified the presence of significant associations between the consequences of intrauterine hypoxia and the levels of nitrates (OR 1.19; 95% CI 1.01-1.40; p=0.042), nitrosothiols (OR 1.19; 95% CI 0.99-1.42; p=0.050) and the polymorphic genotype 4aa/ab of the eNOS gene (OR 0.28; 95% CI 0.12-0.67; p=0.004). Analysis of systemic hemodynamics revealed no significant differences in baseline values between preterm infants with and without intrauterine hypoxia, but we did observe an association with urine output on day 3 of life. To finally clarify the complex influence of indicators of nitrate metabolism on the development of intrauterine hypoxia and to predict the development of consequences of this condition in premature infants, the following indicators are included in the regression prognostic model: the level of nitrates, nitrites, 4aa/4ab genotype and urine output on the third day of life. As the research results show, there is a direct reliable relationship with nitrates and an inverse relationship with nitrites, 4aa/4ab genotype and urine output. This prediction model has high operating characteristics - the area under the ROC curve is 0.8168. Some mechanisms of the influence of maternal metabolic syndrome on the development of relevant disorders in newborns are known, including disorders of nitric oxide synthesis, endothelial dysfunction, and oxidative stress. In our study, the consequences of intrauterine hypoxia were reliably associated with an increase in the concentration of urinary nitrates and a decrease in nitrites, as well as the absence of the 4aa/ab genotype, which is associated with reduced release of nitric oxide. There is evidence that nitric oxide can have both protective and deleterious effects, depending on factors such as nitric oxide synthase isoform and duration of exposure to hypoxia. Conclusions. In preterm infants born to mothers with metabolic syndrome, elevated urinary nitrate levels and the absence of the eNOS 4aa/ab genotype increase the likelihood of suffering the consequences of intrauterine hypoxia. [ABSTRACT FROM AUTHOR]

Cytoglobin (Cygb) has been identified as the major nitric oxide (NO) metabolizing protein in vascular smooth muscle cells (VSMCs) and is crucial for the regulation of vascular tone. In the presence of its requisite cytochrome B5a (B5)/B5 reductase-isoform-3 (B5R) reducing system, Cygb controls NO metabolism through the oxygen-dependent process of NO dioxygenation. Tobacco cigarette smoking (TCS) induces vascular dysfunction; however, the role of Cygb in the pathophysiology of TCS-induced cardiovascular disease has not been previously investigated. While TCS impairs NO biosynthesis, its effect on NO metabolism remains unclear. Therefore, we performed studies in aortic VSMCs with tobacco smoke extract (TSE) exposure to investigate the effects of cigarette smoke constituents on the rates of NO decay, with focus on the alterations that occur in the process of Cygb-mediated NO metabolism. TSE greatly enhanced the rates of NO metabolism by VSMCs. An initial increase in superoxide-mediated NO degradation was seen at 4 h of exposure. This was followed by much larger progressive increases at 24 and 48 h, accompanied by parallel increases in the expression of Cygb and B5/B5R. siRNA-mediated Cygb knockdown greatly decreased these TSE-induced elevations in NO decay rates. Therefore, upregulation of the levels of Cygb and its reducing system accounted for the large increase in NO metabolism rate seen after 24 h of TSE exposure. Thus, increased Cygb-mediated NO degradation would contribute to TCS-induced vascular dysfunction and partial inhibition of Cygb expression or its NO dioxygenase function could be a promising therapeutic target to prevent secondary cardiovascular disease. • Cytoglobin controls nitric oxide (NO) metabolism through NO dioxygenation. • Tobacco smoking exposure induces loss of vascular NO; however, the cause was unknown. • Vascular smooth muscle cell exposure first triggered increased superoxide generation. • This was followed by induction of cytoglobin and the B5/B5R reducing system. • Together, this greatly increased the rate of NO decay in vascular smooth muscle cells. [ABSTRACT FROM AUTHOR]

Symptoms of COVID-19 range from asymptomatic/mild symptoms to severe illness and death, consequence of an excessive inflammatory process triggered by SARS-CoV-2 infection. The diffuse inflammation leads to endothelium dysfunction in pulmonary blood vessels, uncoupling eNOS activity, lowering NO production, causing pulmonary physiological alterations and coagulopathy. On the other hand, iNOS activity is increased, which may be advantageous for host defense, once NO plays antiviral effects. However, overproduction of NO may be deleterious, generating a pro-inflammatory effect. In this review, we discussed the role of endogenous NO as a protective or deleterious agent of the respiratory and vascular systems, the most affected in COVID-19 patients, focusing on eNOS and iNOS roles. We also reviewed the currently available NO therapies and pointed out possible alternative treatments targeting NO metabolism, which could help mitigate health crises in the present and future CoV's spillovers. [Display omitted] • Pathophysiological alterations due to SARS-CoV-2 infection lead to an imbalance NO production. • Reduction of eNOS-derived NO production causes endothelial dysfunction, which represents a risk factor for sever COVID-19. • Excessive iNOS-mediated NO production promotes peroxynitrite formation, which generates several cellular damages. • Therapies that regulate NO bioavailability and production could be the answer for dealing with the present and futures CoV's spillovers. [ABSTRACT FROM AUTHOR]

The effect of low-level laser therapy (LLLT) on the cardiovascular system is not fully established. Since the endothelium is an important endocrine element, establishing the mechanisms of LLLT action is an important issue.The aim of the study was to evaluate the effect of transdermal LLLT on endothelial function.In this study, healthy volunteers (n = 40, age = 20-40 years) were enrolled. N = 30 (14 female, 16 male, mean age 30 ± 5 years) constituted the laser-irradiated group (LG). The remaining 10 subjects (6 women, 4 men, mean age 28 ± 5 years) constituted the control group (CG). Participants were subjected to LLLT once a day for three consecutive days. Blood for biochemical assessments was drawn before the first irradiation and 24 h after the last session. In the LG, transdermal illumination of radial artery was conducted (a semiconductor laser λ = 808 nm, irradiation 50 mW, energy density 1.6 W/cm(2) and a dose 20 J/day, a total dose of 60 J). Biochemical parameters (reflecting angiogenesis: vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiostatin; antioxidative status: glutathione (GSH) and the nitric oxide metabolic pathway: symmetric dimethylarginine (SDMA), asymmetric dimethylarginine (ADMA) and L-arginine) were assessed. In the LG, a significant increase in GSH levels and considerable decrease in angiostatin concentration following the LLLT were observed. No significant differences in levels of the VEGF, FGF, SDMA, ADMA were observed.LLLT modifies vascular endothelial function by increasing its antioxidant and angiogenic potential. We found no significant differences in levels of the nitric oxide pathway metabolites within 24 h following the LLLT irradiation. [ABSTRACT FROM AUTHOR]

Our aim was to investigate the effects of an exercise test on some indices of oxidative status and endothelial function, in trained and untrained subjects. We examined lipid peroxidation, nitric oxide metabolites (NOx) and their ratio before and after a cardiopulmonary test, using a cycloergometer. We enrolled 60 male subjects who practiced sport unprofessionally, subdivided in two groups (A and B) according to the values of VO2max. Group A included sportsmen with poor or fair aerobic fitness (VO2max <39 ml/Kg/min), group B sportsmen with average to excellent aerobic fitness (VO2max >39 ml/Kg/min). The control group included 19 male sedentary subjects. Lipid peroxidation was evaluated by detection of the thiobarbituric acid-reactive substances (TBARS); the NOx were evaluated employing the Griess reagent. At rest, in comparison with sedentary controls, an increase in TBARS, NOx and TBARS/NOx ratio was found in all sportsmen and partially in the two groups. After the cardiopulmonary test, the increase of TBARS and TBARS/NOx ratio was significantly more evident in sedentary controls than in sportsmen. No variation was observed for NOx in any group. These data suggest that sportsmen are protected against the acute oxidative stress induced by an exercise test, and that protection is not strictly dependent on the aerobic fitness. [ABSTRACT FROM AUTHOR]

Effects of a chronic combined unpredictable stress on activities of two cell death-related proteases, calpain and cathepsin B, were studied along with indices of nitrergic system in rat brain structures. Male Wistar rats were subjected to a 2-week-long combined stress (combination of unpaired flash light and moderate footshock associated with a white noise session). Stress resulted in a significant loss in the body and thymus weight and increased defecation in the open field test, though neither motor and exploratory activity, nor plasma corticosterone differed from the respective control levels. Decreased calpain activity and increased cathepsin B activity were demonstrated in the hippocampus of stressed rats (previously we have shown that caspase-3 activity was significantly suppressed in the brain of rats subjected to same type of stress). A significant reduction in the number of NOS-containing neurons was accompanied by a chronic stressinduced decline in NOS activity in the neocortex. Similar changes were observed in the hippocampus. However, levels of NO metabolites were elevated in both structures. Thus, stress-induced structural modifications in the brain may be mediated by disturbances in the nitrergic system and increased lysosomal proteolysis. [ABSTRACT FROM AUTHOR]

Aim Alpha-thalassaemia is known to reduce intra-erythrocyte Hb S (sickle haemoglobin) concentration in sickle cell trait ( SCT) subjects. Because Hb S was shown to increase oxidative stress, the purpose of this study was to assess the effects of the coexistence of α-thalassaemia and SCT on oxidative stress markers and nitric oxide ( NO) metabolism after an acute physical exercise. Methods Forty subjects (age: 23.5 ± 2.21 years), SCT carriers ( Hb AS) or healthy subjects ( Hb AA), with (-α T) or without (- Nα T) an associated α-thalassaemia took part in the study. Plasma markers of oxidative stress [advanced oxidation protein products ( AOPP), protein carbonyl, malondialdehyde ( MDA) and nitrotyrosine], anti-oxidant defences and NO metabolism ( NOx) were measured at rest ( Trest), immediately following an incremental maximal exercise test ( Tex) and during recovery ( T1h, T2h and T24h). Results Malondialdehyde expressed as the percentage of changes from baseline was significantly higher in the Hb AS- Nα T compared with Hb AS-α T during recovery (+36.3 ± 14.1% vs. −1.8 ± 13.2% at T1h, P = 0.02; +36.6 ± 13.4% vs. −11.4 ± 12.5% at T2h, P = 0.004 and +24.1 ± 12.3% vs. −14.4 ± 11.5% at T24h, P = 0.02 in Hb AS- Nα T vs. Hb AS-α T). Compared with Hb AS- Nα T, Hb AS-α T had a higher NOx change from baseline at Tex (−23.4 ± 20.6% vs. +57.7 ± 19.3%, respectively; P = 0.005) and lower nitrotyrosine change from baseline at T1h (+7.2 ± 22.2% vs. +93.5%±29.3%, respectively; P = 0.04). Conclusion All these data suggest that the presence of α-thalassaemia may blunt the higher level of oxidative stress and the impaired bioavailability of NO observed in the SCT carriers. [ABSTRACT FROM AUTHOR]

Cytochrome c (cyt c)-derived protein radicals, radical adduct aggregates, and protein tyrosine nitration have been implicated in the pro-apoptotic event connecting inflammation to the development of diseases. During inflammation, one of the reactive oxygen species metabolized via neutrophil activation is hypochlorite (HOCl); destruction of the mitochondrial electron transport chain by hypochlorite is considered to be a damaging factor. Previous study has shown that HOCl induces the site-specific oxidation of cyt c at met-80. In this work, we have assessed the hypothesis that exposure of cyt c to physiologically relevant concentrations of HOCl leads to protein-derived radical and consequent protein aggregation, which subsequently affects cyt c′s regulation of nitric oxide metabolism. Reaction intermediates, chemical pathways available for protein aggregation, and protein nitration were examined. A weak ESR signal for immobilized nitroxide derived from the protein was detected when a high concentration of cyt c was reacted with hypochlorite in the presence of the nitroso spin trap 2-methyl-2-nitrosopropane. When a low concentration of cyt c was exposed to the physiologically relevant levels of HOCl in the presence of 5,5-dimethyl-pyrroline N-oxide (DMPO), we detected DMPO nitrone adducts derived from both protein and protein aggregate radicals as assessed by Western blot using an antibody raised against the DMPO nitrone adduct. The cyt c-derived protein radicals formed by HOCl were located on lysine and tyrosine residues, with lysine predominating. Cyt c-derived protein aggregates induced by HOCl involved primarily lysine residues and hydrophobic interaction. In addition, HOCl-oxidized cyt c (HOCl-cyt c) exhibited a higher affinity for NO and enhancement of nonenzymatic NO synthesis from nitrite reduction. Furthermore, HOCl-mediated cyt c oxidation also resulted in a significant elevation of cyt c nitration derived from either NO trapping of the cyt c-derived tyrosyl radical or cyt c-catalyzed one-electron oxidation of nitrite. [Copyright &y& Elsevier]

• The AlaxoLito Plus Nasal Stent does not increase exercise performance or oxygen uptake. • RBC deformability changes depending on breathing mode and intensity. • Exhaled NO increases with stent applications compared to oral/nasal breathing. • Blood NO concentrations are not affected. To investigate the influence of the intranasal AlaxoLito Plus Nasal Stent during exercise on nitric oxide (NO) synthesis, NO exhalation, red blood cell (RBC) deformability and oxygen uptake. Parameters were measured before and after acute cycle ergometer test at different intensities. Spirometric, microrheological and NO parameters were determined for oral (OB), nasal (NB) and nasal-stent breathing (SB). RBC deformability was measured and elongation indices for 3.87 Pa and maximal deformability were calculated. RBC/plasma/exhaled NO, oxygen uptake and respiratory rate were determined. Exhaled NO was higher at rest during OB compared to SB and NB and decreased after exercise with NB and SB. Plasma and RBC NO remained unaltered during intervention. RBC deformability increased at moderate intensity during SB. Deformability decreased at moderate and medium intensity with NB. Respiratory rate for same oxygen uptake did not differ between breathing settings. The AlaxoLito Plus Nasal Stent may modulate deformability during moderate exercise and increase NO exhalation without major effects on oxygen uptake and performance. [ABSTRACT FROM AUTHOR]