20 results on '"Spustová"'
Search Results
2. Lipid peroxidation and nutrition
- Author
-
M Krajčovičová-Kudláčková, V Spustová, and V Pauková
- Subjects
Physiology ,General Medicine - Abstract
Levels of conjugated dienes of fatty acids (first peroxidation product) in relation to their substrates and promotors (triacylglycerols, homocysteine, iron) as well as to their inhibitors (essential antioxidative vitamins) were assessed in a vegetarian group (n=24) and compared with subjects on a mixed diet (traditional nutrition, n=24). Positive significant linear correlation between conjugated dienes and triacylglycerols, homocysteine, iron as well as inverse relationship between conjugated dienes and vitamin E, vitamin C, beta-carotene were observed in pooled groups. Lipid peroxidation risk in vegetarians seems to be caused predominantly by hyperhomocysteinemia, whereas in a mixed diet group this was due to a higher supply of substrates or risk iron values. The incidence of only 8 % of risk conjugated diene values in vegetarians in contrast to 42 % in the group with traditional diet indicates that vegetarians have a better antioxidative status as a consequence of regular consumption of protective food.
- Published
- 2004
3. The Effect of Vitamin D3 Supplementation on Intracellular Calcium and Plasma Membrane Calcium ATPase Activity in Early Stages of Chronic Kidney Disease
- Author
-
MORVOVÁ, M., primary, LAJDOVÁ, I., additional, SPUSTOVÁ, V., additional, ZVARÍK, M., additional, and ŠIKUROVÁ, L., additional
- Published
- 2014
- Full Text
- View/download PDF
4. Does magnesium dysbalance participate in the development of insulin resistance in early stages of renal disease?
- Author
-
K, Sebeková, K, Stefíková, D, Polakovicová, V, Spustová, and R, Dzúrik
- Subjects
Adult ,Male ,Erythrocytes ,Nephrosclerosis ,Glucose Tolerance Test ,Middle Aged ,Water-Electrolyte Balance ,Body Mass Index ,Glomerulonephritis ,Humans ,Nephritis, Interstitial ,Female ,Kidney Diseases ,Magnesium ,Insulin Resistance - Abstract
We investigated the potential role of magnesium (Mg) dysbalance in the pathogenesis of insulin resistance (IR) in patients with mildly-to-moderately decreased renal function (creatinine: 142.8+/-11.0 mmol/l). The data were compared to those of 8 age- and sex-matched healthy controls (CTRL). The standard oral glucose tolerance test (oGTT) was performed in 61 patients. Twenty-two patients were classified as IR according to their values on fasting and after-load immunoreactive insulin concentrations. Serum and total erythrocyte Mg (tErMg) (atomic absorption spectro-photometry) and free erythrocyte Mg (fErMg) concentrations ((31) P NMR spectroscopy) were determined prior to and two hours after the glucose load. Ten out of 39 insulin-sensitive (IS) patients, but only one out of 22 insulin-resistant (IR) patients, had a low basal fErMg concentration (162.2 micromol/l, chi2, p0.01). IR patients had higher serum Mg, total erythrocyte Mg and bound erythrocyte Mg (bErMg) concentrations (both before and after glucose load) when compared with the IS group. Both groups responded to the glucose load with a significant decrease in serum Mg concentration (within the normal range), while the IR group also exhibited a decline in tErMg and bErMg. The mean sum of insulin needed to metabolize the same glucose load correlated positively with tErMg (r=0.545, p0.01) and bErMg (r=0.560, p0.01) in the IR patients. It is concluded that, at an early stage of renal dysfunction, IR is not associated with the decline in free erythrocyte Mg concentration, but the magnesium handling in red blood cells is altered.
- Published
- 2003
5. Serum ex vivo lipoprotein oxidizability in patients with ischemic heart disease supplemented with vitamin E
- Author
-
A, Nagyová, V, Mongiellová, Z, Krivosíková, P, Blazícek, V, Spustová, M, Gajdos, and R, Dzúrik
- Subjects
Adult ,Male ,Lipoproteins ,Hypercholesterolemia ,Myocardial Ischemia ,Coronary Disease ,Middle Aged ,Antioxidants ,Postmenopause ,Humans ,Vitamin E ,Female ,Oxidation-Reduction ,Aged - Abstract
The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma alpha-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women. Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease.
- Published
- 2002
6. Acute effect of hydrochlorothiazide on renal calcium and magnesium handling in postmenopausal women
- Author
-
K, Stefíková, V, Spustová, and R, Dzúrik
- Subjects
Postmenopause ,Hydrochlorothiazide ,Kidney Tubules ,Sodium Chloride Symporter Inhibitors ,Humans ,Calcium ,Female ,Magnesium ,Diuretics ,Kidney ,Potassium Deficiency ,Absorption ,Phosphates - Abstract
A single 50 mg dose of hydrochlorothiazide (HCTZ) decreases the urinary excretion of calcium (U(Ca)V), clearance (C(Ca)) and fractional excretion (FE(Ca)) of calcium. This is accompanied by an increase of total calcium and ionized calcium (Ca2+) concentrations in the serum. On the other hand, HCTZ increases fractional excretion of magnesium (FE(Mg)) and decreases serum Mg2+ concentrations. Moreover, HCTZ decreases markedly clearance of phosphate (C(Pi)) and fractional excretion of phosphate (FE(Pi)) and increases serum phosphate (Pi) concentrations in healthy postmenopausal women. It is concluded that intrinsic renal cellular control promptly uncouples calcium and magnesium tubular reabsorption even without K+ depletion.
- Published
- 2000
7. Participation of P-dependent and P-independent glutaminases in rat kidney ammoniagenesis and their modulation by metabolic acidosis, hippurate and insulin
- Author
-
Z, Krivosíková, V, Spustová, and R, Dzúrik
- Subjects
Male ,Kidney Cortex ,Glutaminase ,Ammonia ,Hippurates ,Animals ,Insulin ,Rats, Wistar ,Acidosis ,Kidney ,Rats - Abstract
The key regulatory enzymes of kidney ammoniagenesis appear to be P-dependent (PDG) and P-independent (PIG) glutaminases. While the participation of PDG has been satisfactorily elucidated, the significance of PIG remains doubtful. Rat kidney cortex slices synthesized ammonia even under basal conditions. Metabolic acidosis, hippurate and insulin stimulated ammonia production. Under basal conditions, PDG activity in kidney homogenate, was twice as high as PIG activity. Metabolic acidosis stimulated ammonia production by the stimulation of both PDG (100%) and PIG (57%) activities. Hippurate stimulated only PIG activity both under basal conditions (90%) and in metabolic acidosis (52%), while it inhibited PDG activity only insignificantly under basal conditions and markedly (53%) in metabolic acidosis. Insulin stimulated both PIG and PDG activities under basal conditions as well as in metabolic acidosis and potentiated the PIG stimulation by hippurate while it potentiated the hippurate inhibition of PDG both under basal conditions and in acidotic rats. In conclusion, both PDG and PIG participate in ammoniagenesis and are stimulated by metabolic acidosis and insulin. Hippurate stimulates PIG, while it inhibits PDG in metabolic acidosis and even after insulin administration. The effect of hippurate appears to be of physiological interest.
- Published
- 1998
8. Insulin Resistance and Vitamin D Deficiency in Patients With Chronic Kidney Disease Stage 2-3
- Author
-
ŠTEFÍKOVÁ, K., primary, SPUSTOVÁ, V., additional, KRIVOŠÍKOVÁ, Z., additional, OKŠA, A., additional, GAZDÍKOVÁ, K., additional, FEDELEŠOVÁ, V., additional, and DZÚRIK, R., additional
- Published
- 2011
- Full Text
- View/download PDF
9. Serum hippurate and its excretion in conservatively treated and dialysed patients with chronic renal failure
- Author
-
V, Spustová, M, Gajdos, K, Opatrný, K, Stefíková, and R, Dzúrik
- Subjects
Reference Values ,Renal Dialysis ,Hippurates ,Osmolar Concentration ,Humans ,Kidney Failure, Chronic - Abstract
54 healthy volunteers or patients with normal kidney and liver function, 17 patients with decreased kidney function and 12 dialysed patients were evaluated for their serum hippurate accumulation and kidney excretion. It was found that there was an inverse relationship between serum hippurate and the clearance of endogenous creatinine (CCr) and a free relationship between fractional excretion of hippurate and CCr. The excretory capacity in residual nephrons was increased. This was caused by the greater glomerular filtration load which increased up to 25 times and tubular secretion which increased 7 times in dialysed patients. The relative contribution of glomerular filtration to hippurate excretion rose from about 20% in controls to almost 50% in dialysed patients. True kidney adaptation was localized in the organic anion transport system of proximal tubules.
- Published
- 1991
10. P-aminohippurate accumulation in kidney cortex slices: stimulation by dicarboxylates, amino acids and their oxoanalogues
- Author
-
R, Dzúrik, M, Geryková, and V, Spustová
- Subjects
Male ,Kidney Cortex ,Dose-Response Relationship, Drug ,Animals ,Dicarboxylic Acids ,Rats, Inbred Strains ,p-Aminohippuric Acid ,Amino Acids ,Rats - Abstract
The effect of various amino acids and oxoacids on the accumulation of PAH in rat kidney cortex slices was determined. The following compounds were found to increase the PAH tissue to medium ratio (T/MPAH): a) dicarboxylic acids: glutarate, 2-oxoglutarate and oxaloacetate, b) amino acids: glutamate, isoleucine, leucine, valine, methionine, tryptophane, histidine, threonine and glycine, c) monocarboxylates: hydroxymethionine, oxovaline, oxoisoleucine and oxoleucine. There were no marked concentration/effect differences to glycine, glutamate, glutarate and oxovaline. Ouabain inhibited T/MPAH only slightly, but abolished its increase by pyruvate, 2-oxoglutarate and histidine. Oxygen hyposaturation abolished the T/MPAH increase caused by 2-oxoglutarate, pyruvate, glutamate and histidine. It is concluded that various substrates stimulating the organic anion transport system (OATS) do so namely by improving the energy supply, although the direct participation of dicarboxylates in OATS could be of relevance namely in short-lasting variations.
- Published
- 1991
11. The Effect of Vitamin D3 Supplementation on Intracellular Calcium and Plasma Membrane Calcium ATPase Activity in Early Stages of Chronic Kidney Disease.
- Author
-
MORVOVÁ Jr., M., LAJDOVÁ, I., SPUSTOVÁ, V., ZVARÍK, M., and ŠIKUROVÁ, L.
- Subjects
VITAMIN D ,KIDNEY diseases ,CELL membranes ,INTRACELLULAR calcium ,PUBLIC health - Abstract
Chronic kidney disease (CKD) is associated with increased concentration of intracellular calcium, which is pathological and may lead to irreversible damage of cell functions and structures. The aim of our study was to investigate the impact of 6 months vitamin D
3 supplementation (14000 IU/week) on free cytosolic calcium concentration ([Ca2+ ]i ) and on the plasma membrane calcium ATPase (PMCA) activity of patients with CKD stage 2-3. PMCA activity of patients was also compared to that of healthy volunteers. Vitamin D3 supplementation of CKD patients resulted in the decrease of [Ca2+ ]i (119.79±5.87 nmol/l vs. 105.36± 3.59 nmol/l, n=14, P<0.001), whereas PMCA activity of CKD patients (38.75±22.89 nmol Pi /mg/h) remained unchanged after vitamin D3 supplementation (40.96±17.74 nmol Pi /mg/h, n=14). PMCA activity of early stage CKD patients before supplementation of vitamin D3 , was reduced by 34% (42.01±20.64 nmol Pi /mg/h) in comparison to healthy volunteers (63.68±20.32 nmol Pi /mg/h, n=28, P<0.001). These results indicate that vitamin D3 supplementation had a lowering effect on [Ca2+ ]i and negligible effect on PMCA activity in CKD patients. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
12. Lipid peroxidation and nutrition.
- Author
-
Krajčovičová-Kudláčková, M, primary, Spustová, V, additional, and Pauková, V, additional
- Published
- 2004
- Full Text
- View/download PDF
13. Serum ex vivo lipoprotein oxidizability in patients with ischemic heart disease supplemented with vitamin E
- Author
-
Mongiellová, V, additional, Krivošíková, Z, additional, Blažíček, P, additional, Spustová, V, additional, Gajdoš, M, additional, and Dzúrik, R, additional
- Published
- 2002
- Full Text
- View/download PDF
14. Does magnesium dysbalance participate in the development of insulin resistance in early stages of renal disease?
- Author
-
Sebeková K, Stefíková K, Polakovicová D, Spustová V, and Dzúrik R
- Subjects
- Adult, Body Mass Index, Erythrocytes metabolism, Female, Glomerulonephritis physiopathology, Glucose Tolerance Test, Humans, Male, Middle Aged, Nephritis, Interstitial physiopathology, Nephrosclerosis physiopathology, Water-Electrolyte Balance physiology, Insulin Resistance physiology, Kidney Diseases physiopathology, Magnesium metabolism
- Abstract
We investigated the potential role of magnesium (Mg) dysbalance in the pathogenesis of insulin resistance (IR) in patients with mildly-to-moderately decreased renal function (creatinine: 142.8+/-11.0 mmol/l). The data were compared to those of 8 age- and sex-matched healthy controls (CTRL). The standard oral glucose tolerance test (oGTT) was performed in 61 patients. Twenty-two patients were classified as IR according to their values on fasting and after-load immunoreactive insulin concentrations. Serum and total erythrocyte Mg (tErMg) (atomic absorption spectro-photometry) and free erythrocyte Mg (fErMg) concentrations ((31) P NMR spectroscopy) were determined prior to and two hours after the glucose load. Ten out of 39 insulin-sensitive (IS) patients, but only one out of 22 insulin-resistant (IR) patients, had a low basal fErMg concentration (<162.2 micromol/l, chi2, p<0.01). IR patients had higher serum Mg, total erythrocyte Mg and bound erythrocyte Mg (bErMg) concentrations (both before and after glucose load) when compared with the IS group. Both groups responded to the glucose load with a significant decrease in serum Mg concentration (within the normal range), while the IR group also exhibited a decline in tErMg and bErMg. The mean sum of insulin needed to metabolize the same glucose load correlated positively with tErMg (r=0.545, p<0.01) and bErMg (r=0.560, p<0.01) in the IR patients. It is concluded that, at an early stage of renal dysfunction, IR is not associated with the decline in free erythrocyte Mg concentration, but the magnesium handling in red blood cells is altered.
- Published
- 2002
15. Serum ex vivo lipoprotein oxidizability in patients with ischemic heart disease supplemented with vitamin E.
- Author
-
Nagyová A, Mongiellová V, Krivosíková Z, Blazícek P, Spustová V, Gajdos M, and Dzúrik R
- Subjects
- Adult, Aged, Coronary Disease blood, Coronary Disease drug therapy, Female, Humans, Hypercholesterolemia blood, Hypercholesterolemia drug therapy, Male, Middle Aged, Oxidation-Reduction, Postmenopause, Antioxidants administration & dosage, Lipoproteins blood, Myocardial Ischemia blood, Myocardial Ischemia drug therapy, Vitamin E administration & dosage
- Abstract
The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma alpha-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women. Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease.
- Published
- 2002
16. Acute effect of hydrochlorothiazide on renal calcium and magnesium handling in postmenopausal women.
- Author
-
Stefíková K, Spustová V, and Dzúrik R
- Subjects
- Absorption, Calcium blood, Calcium urine, Diuretics, Female, Humans, Kidney metabolism, Kidney Tubules metabolism, Magnesium blood, Magnesium urine, Phosphates blood, Phosphates urine, Potassium Deficiency, Calcium metabolism, Hydrochlorothiazide pharmacology, Kidney drug effects, Magnesium metabolism, Postmenopause, Sodium Chloride Symporter Inhibitors pharmacology
- Abstract
A single 50 mg dose of hydrochlorothiazide (HCTZ) decreases the urinary excretion of calcium (U(Ca)V), clearance (C(Ca)) and fractional excretion (FE(Ca)) of calcium. This is accompanied by an increase of total calcium and ionized calcium (Ca2+) concentrations in the serum. On the other hand, HCTZ increases fractional excretion of magnesium (FE(Mg)) and decreases serum Mg2+ concentrations. Moreover, HCTZ decreases markedly clearance of phosphate (C(Pi)) and fractional excretion of phosphate (FE(Pi)) and increases serum phosphate (Pi) concentrations in healthy postmenopausal women. It is concluded that intrinsic renal cellular control promptly uncouples calcium and magnesium tubular reabsorption even without K+ depletion.
- Published
- 1999
17. Enalapril in subantihypertensive dosage attenuates kidney proliferation and functional recovery in normotensive ablation nephropathy of the rat.
- Author
-
Krivosíková Z, Sebeková K, Spustová V, Lajdová I, and Dzúrik R
- Subjects
- Animals, Blood Pressure, Blood Urea Nitrogen, Cell Division drug effects, Collagen metabolism, Creatinine urine, Dose-Response Relationship, Drug, Hyperplasia, Hypertension, Renal pathology, Hypertension, Renal physiopathology, Hypertrophy, Kidney surgery, Male, Nephrectomy, Organ Size, Proteinuria drug therapy, Proteinuria pathology, Proteinuria physiopathology, Rats, Rats, Wistar, Angiotensin-Converting Enzyme Inhibitors pharmacology, Enalapril pharmacology, Hypertension, Renal drug therapy, Kidney pathology, Kidney physiology
- Abstract
Most studies on the antiproliferative action of angiotensin converting enzyme inhibitors (ACEI) were performed in a rat hypertensive remnant kidney model with 5/6 kidney ablation which raised objections about the antihypertensive effect of ACEI and the influence of other antihypertensive drugs administered to remnant kidney control rats. To prevent these objections, a normotensive 4/6 remnant kidney model was elaborated and a subantihypertensive dosage of enalapril was used to evaluate its antiproliferative action. Subtotally nephrectomized rats (Nx) markedly increased the remnant kidney weight during a 4-week period and this rise was prevented by the treatment with enalapril (NxE) (Nx +297+/-35 mg vs. sham-operated +145+/-32 mg, p<0.001; NxE +154+/-35 mg vs. Nx p<0.001). While collagen concentration in the kidney cortex was not increased in sham-operated rats (Sham) in comparison with the control group (Ctrl) at the beginning of the study, the subsequent increase was significant in the Nx group and enalapril did not attenuate this increase (Sham 148+/-5 mg/100 g w.w. vs. Nx 164+/-2 mg/100 g w.w., p<0.01; NxE 161+/-4 mg/100 g w.w. vs. Sham p<0.05). The tubular protein/DNA ratio increase, which was significant in the Nx group, was inhibited by enalapril (Nx 26.2+/-10.5 vs. NxE 15.3+/-2.6, p<0.05). The protein/DNA ratio was much lower in glomeruli, with no significant changes in either the Nx or NxE groups. Serum urea concentrations were slightly higher in the Nx group than in the sham-operated group, but markedly elevated in the NxE group (Nx 10.71+/-0.76 mmol/l vs. Sham 6.10+/-0.33 mmol/l, p<0.001; NxE 28.9+/-2.6 mmol/l vs. Sham p<0.001). Creatinine concentrations in the Nx group were increased in comparison with the sham-operated group and markedly increased in the NxE group (Nx 63.7+/-3.56 micromol/l vs. Sham 37.2+/-2.84 micromol/l, p<0.001; NxE 107.0+/-5.2 micromol/l vs. Sham p<0.001). The clearance of creatinine was lower in the Nx group than in the sham-operated group and was markedly reduced in the NxE group (Nx 0.89+/-0.06 ml/min.g kidney wt. vs. Sham 1.05+/-0.16 ml/min x g kidney wt., p<0.01; NxE 0.58+/-0.029 ml/min x g kidney wt. vs. Sham, p<0.001). Enalapril improved proteinuria in comparison with the Nx group (NxE 5.6+/-0.6 mg/24 h vs. Nx 16.1+/-3.4 mg/24 h, p<0.05). Thus remnant kidney proliferation is substantial even in normotensive rats. It includes both proliferation and collagen accumulation with partial recovery of kidney weight and function, but is accompanied by enhanced proteinuria. Enalapril attenuates the proliferation and decreases proteinuria but prolongs kidney function recovery.
- Published
- 1999
18. Participation of P-dependent and P-independent glutaminases in rat kidney ammoniagenesis and their modulation by metabolic acidosis, hippurate and insulin.
- Author
-
Krivosíková Z, Spustová V, and Dzúrik R
- Subjects
- Animals, Kidney metabolism, Kidney Cortex metabolism, Male, Rats, Rats, Wistar, Acidosis metabolism, Ammonia metabolism, Glutaminase metabolism, Hippurates metabolism, Insulin metabolism, Kidney enzymology
- Abstract
The key regulatory enzymes of kidney ammoniagenesis appear to be P-dependent (PDG) and P-independent (PIG) glutaminases. While the participation of PDG has been satisfactorily elucidated, the significance of PIG remains doubtful. Rat kidney cortex slices synthesized ammonia even under basal conditions. Metabolic acidosis, hippurate and insulin stimulated ammonia production. Under basal conditions, PDG activity in kidney homogenate, was twice as high as PIG activity. Metabolic acidosis stimulated ammonia production by the stimulation of both PDG (100%) and PIG (57%) activities. Hippurate stimulated only PIG activity both under basal conditions (90%) and in metabolic acidosis (52%), while it inhibited PDG activity only insignificantly under basal conditions and markedly (53%) in metabolic acidosis. Insulin stimulated both PIG and PDG activities under basal conditions as well as in metabolic acidosis and potentiated the PIG stimulation by hippurate while it potentiated the hippurate inhibition of PDG both under basal conditions and in acidotic rats. In conclusion, both PDG and PIG participate in ammoniagenesis and are stimulated by metabolic acidosis and insulin. Hippurate stimulates PIG, while it inhibits PDG in metabolic acidosis and even after insulin administration. The effect of hippurate appears to be of physiological interest.
- Published
- 1998
19. Serum hippurate and its excretion in conservatively treated and dialysed patients with chronic renal failure.
- Author
-
Spustová V, Gajdos M, Opatrný K Jr, Stefíková K, and Dzúrik R
- Subjects
- Hippurates urine, Humans, Kidney Failure, Chronic therapy, Kidney Failure, Chronic urine, Osmolar Concentration, Reference Values, Hippurates blood, Kidney Failure, Chronic blood, Renal Dialysis
- Abstract
54 healthy volunteers or patients with normal kidney and liver function, 17 patients with decreased kidney function and 12 dialysed patients were evaluated for their serum hippurate accumulation and kidney excretion. It was found that there was an inverse relationship between serum hippurate and the clearance of endogenous creatinine (CCr) and a free relationship between fractional excretion of hippurate and CCr. The excretory capacity in residual nephrons was increased. This was caused by the greater glomerular filtration load which increased up to 25 times and tubular secretion which increased 7 times in dialysed patients. The relative contribution of glomerular filtration to hippurate excretion rose from about 20% in controls to almost 50% in dialysed patients. True kidney adaptation was localized in the organic anion transport system of proximal tubules.
- Published
- 1991
20. P-aminohippurate accumulation in kidney cortex slices: stimulation by dicarboxylates, amino acids and their oxoanalogues.
- Author
-
Dzúrik R, Geryková M, and Spustová V
- Subjects
- Animals, Dose-Response Relationship, Drug, Kidney Cortex drug effects, Male, Rats, Rats, Inbred Strains, Amino Acids pharmacology, Dicarboxylic Acids pharmacology, Kidney Cortex metabolism, p-Aminohippuric Acid metabolism
- Abstract
The effect of various amino acids and oxoacids on the accumulation of PAH in rat kidney cortex slices was determined. The following compounds were found to increase the PAH tissue to medium ratio (T/MPAH): a) dicarboxylic acids: glutarate, 2-oxoglutarate and oxaloacetate, b) amino acids: glutamate, isoleucine, leucine, valine, methionine, tryptophane, histidine, threonine and glycine, c) monocarboxylates: hydroxymethionine, oxovaline, oxoisoleucine and oxoleucine. There were no marked concentration/effect differences to glycine, glutamate, glutarate and oxovaline. Ouabain inhibited T/MPAH only slightly, but abolished its increase by pyruvate, 2-oxoglutarate and histidine. Oxygen hyposaturation abolished the T/MPAH increase caused by 2-oxoglutarate, pyruvate, glutamate and histidine. It is concluded that various substrates stimulating the organic anion transport system (OATS) do so namely by improving the energy supply, although the direct participation of dicarboxylates in OATS could be of relevance namely in short-lasting variations.
- Published
- 1991
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