Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sodium azide (AZ) is a nitrovasodilator with diverse biochemical properties. We found that low doses of AZ led to a profound protective effect against postischemic, acute renal failure (ARF) in rats. AZ, given at 250 micrograms/kg iv, before 25 min of renal artery occlusion (RAO) and again before reperfusion, conferred almost complete protection against loss of kidney function determined 18 h after RAO. The effect of AZ was evidenced by a higher creatinine clearance (+348%) and lower levels of blood urea nitrogen (-69%) and histological renal damage (-50%) compared with ischemic control animals. Indexes of kidney function in AZ-treated animals subjected to RAO were not significantly different from those of nonischemic control animals. Two other nitrovasodilators, sodium nitroprusside and hydralazine, at doses which produced decreases in blood pressure similar to that of AZ, were ineffective at preventing ARF. The beneficial effect of AZ may be due to its known ability to inhibit one or more enzymes including adenosinetriphosphatase, cytochrome-c oxidase, and myeloperoxidase.
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PMID:Sodium azide protects against ischemia-induced acute renal failure in rats. 834 10

1. Uridine and uridine monophosphate (UMP) are natriuretic and a vasopressor in intact rats. In deoxycorticosterone acetate (DOCA)-salt hypertensive rats metabolic clearance rate (MCR) of uridine is raised and basal plasma uridine diminished, suggesting that metabolism of uridine is linked to changes in extracellular space. 2. Plasma uridine concentration was raised in 38 patients with chronic renal failure compared with age- and sex-matched healthy controls (8.49 mumol/L, 4.37-13.74 mumol/L median, interquartile range, and 2.64 mumol/L 2.51-2.74 mumol/L, respectively, P < 0.001). Plasma uridine was significantly diminished after isotonic fluid removal by ultrafiltration (UF) from 7.25 mumol/L (3.7-11.08) to 5.07 mumol/L (3.3-8.3), P < 0.001, whereas concentration of marker solutes urea and creatinine remained unchanged. During haemodialysis (HD), plasma uridine fell significantly from its pre-HD level. 3. In an animal model of expanded extracellular space the one-kidney, one-clip rat, plasma uridine was significantly higher (20.56 +/- 1.19 mumol/L, P < 0.01) and MCR diminished (34.93 +/- 3.44 mL/kg per min, P < 0.01) compared with sham-operated animals (plasma uridine 12.14 +/- 1.07 and MCR 53.59 +/- 4.11 mL/kg per min). Uridine or UMP did not inhibit Na+, K(+)-ATPase in either of the two assay systems. 4. It was concluded that catabolism of uridine is reduced by extracellular expansion and probably increased by volume reduction by UF.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolism of uridine in expanded extracellular volume states. 839 45

The effects of feeding a 1% corn oil-9% menhaden oil or beef tallow diet on the early phase of diabetic nephropathy in BHE/cdb rats was studied. The diet groups were subdivided into rats with or without impaired glucose tolerance. Those fed menhaden oil had renal hypertrophy, mild albuminuria, decreased creatinine clearance, increased urea clearance, and more severe lesion scores than rats fed beef tallow. No differences in glomerular filtration rate, Na+, K+-ATPase activity, sorbitol dehydrogenase, or inositol 1, 4, 5-phosphate were observed. Beef tallow-fed rats had higher serum triglyceride levels and renal cholesterol levels. Renal and hepatic fatty acid profiles reflected the fatty acid profile of the dietary fat. These results suggest that beef tallow conferred a protective effect on the renal tissues of these diabetes-prone rats.
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PMID:Early renal disease in BHE/cdb rats is less in rats fed beef tallow than in rats fed menhaden oil. 850 57

1. The effects of two non-steroidal anti-inflammatory drugs, ibuprofen (20 mg day-1 kg-1) and diclofenac sodium (2.5 mg day-1 kg-1), on the severity of gentamicin-induced nephrotoxicity were evaluated in rats. 2. Administration of gentamicin (100 mg day-1 kg-1) for 5 days resulted in a significant increase in renal cortical total phospholipids accompanied by a significant decrease in cortical Na+, K(+)-ATPase activity. These changes were associated with a significant decrease in body weight and increases in kidney weight, serum creatinine and urea nitrogen. 3. In rats treated simultaneously with both gentamicin and either ibuprofen or diclofenac sodium for 5 days, all the measured parameters of renal dysfunction were similar in magnitude to those observed in rats treated with gentamicin alone. 4. In contrast, rats treated with either ibuprofen or diclofenac sodium for 27 days and injected concurrently with gentamicin during the last 5 days of the treatment period had significantly higher kidney weight, lower renal cortical Na+, K(+)-ATPase activity and higher cortical phospholipid content, serum creatinine and urea nitrogen than did rats treated with gentamicin alone. A 27-day treatment with ibuprofen or diclofenac sodium alone resulted in no change in renal function. 5. These results demonstrate that gentamicin nephrotoxicity was potentiated after the long (27 days) but not after the short (5 days) period of treatment with ibuprofen and diclofenac sodium. Thus, prolonged administration of non-steroidal anti-inflammatory drugs should be considered as a risk factor that may increase the nephrotoxic potential of gentamicin.
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PMID:Assessment of gentamicin-induced nephrotoxicity in rats treated with low doses of ibuprofen and diclofenac sodium. 879 33

1. Unilateral left renal artery occlusion for 1 h in a group of 8 untreated female Sprague-Dawley rats resulted in oliguric acute renal failure (ARF) persisting for more than 6 h after reflow, i.e. after reperfusion of the kidney by removal of the arterial clamp. In a second group of 8 rats with left unilateral ARF the effects of levemopamil (L), a calcium entry blocker with 5-hydroxytryptamine2 (5-HT2) receptor antagonistic properties, were studied. Rats received L as a continuous infusion (6 mg kg-1 h-1) from 1 h before ischaemia until 6 h after reflow. 2. Endogenous creatinine clearance, an estimate of glomerular filtration rate (GFR), of left ischaemic kidneys of untreated rats was almost completely abolished and urine flow was 0.05 +/- 0.02 and 0.03 +/- 0.01 ml h-1 100 g-1 body weight (body wt.) at 2 and at 6 h of reflow, respectively. In contrast, left ischaemic kidneys of L-treated rats revealed significantly higher GFR (0.10 +/- 0.02 and 0.03 +/- 0.01 ml min-1 g-1 kidney weight (k.wt.); P < 0.01) and urine flow (0.51 +/- 0.05 and 0.15 +/- 0.04 ml h-1 100 g-1 body wt.; P < 0.05) at 2 and 6 h of reflow, respectively. 3. At 6 h of reflow, mitochondria from the cortex of left ischaemic kidneys of untreated rats showed significantly reduced ATP synthesis when compared to right intact kidneys (0.06 +/- 0.02 vs 0.26 +/- 0.02 mumol ATP mg-1 protein min-1 (P < 0.01)). In contrast, in L-treated rats, ATP synthesis of left ischaemic kidneys was largely preserved (0.17 +/- 0.01 mumol ATP mg-1 protein min-1). 4. Ischaemia of left kidneys resulted in a significant decrease in medullary Na-K-ATPase activity to 9.6 +/- 2.4 as compared to 20.4 +/- 3.7 mumol P(i) h-1 mg-1 protein in the intact right kidneys which was not prevented by L (9.4 +/- 2.4 mumol P(i) h-1 mg-1 protein). 5. In untreated rats the calcium content in cortical mitochondria from left ischaemic kidneys had risen 2 fold to 23.0 +/- 1.8 at 6 h of reflow as compared to 12.2 +/- 0.3 nmol mg-1 protein in right intact kidneys (P < 0.01). This rise in mitochondrial calcium was not significantly attenuated by treatment with L (19.9 +/- 1.7 nmol mg-1 protein). 6. The results show that L transiently converted oliguria into non-oliguria during the early phase after reflow in ischaemic ARF, i.e. after reperfusion following 1 h of complete interruption of renal perfusion. The present data suggest indirectly that the 5-HT2-antagonistic properties of L rather than its calcium channel blocking action maintains GFR at low level and protects mitochondrial function early after reflow in this model of ischaemic ARF.
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PMID:Calcium entry and 5-HT2 receptor blockade in oliguric ischaemic acute renal failure: effects of levemopamil in conscious rats. 888 35

Erythrocyte sodium-potassium (Na+/K+)-ATPase and sodium-lithium (Na+/Li+) countertransport activities were measured in 18 children (aged 9.6 years, range 6-16 years) with idiopathic hypercalciuria (IHU) to evaluate cellular Na handling. The effect of chronic thiazide administration on these parameters and on bone mineral density was also evaluated. Patients with IHU had significantly lower erythrocyte Na+/K+-ATPase activity than 23 age-matched healthy controls (mean +/- SEM 2,156 +/- 110 micromol P/l erythrocyte per hour vs. 3,165 +/- 175, P < 0.01). Thiazide treatment significantly lowered urinary calcium excretion; this was followed by a slight suppression of intact parathyroid hormone (iPTH). The urinary calcium/creatinine ratio before and during treatment was 0.90 +/- 0.07 mmol/mmol versus 0.51 +/- 0.06 respectively, P < 0.01. The corresponding iPTH levels were 5.9 +/- 0.6 pmol/l and 5.1 +/- 0.7, P < 0.05. The Na+/K+-ATPase activity increased significantly (2,769 +/- 169 micromol P/l erythrocyte per hour vs. 2,156 +/- 110 in the control period, P < 0.01) and the Na+/Li+ countertransport decreased (268 +/- 28 micromol Li/l erythrocyte per hour vs. 328+26 in the control period, P < 0.03). The bone mineral density Z score rose from -1.3 +/- 0.26 to -0.8 +/- 0.22 (P < 0.03). We conclude that IHU is accompanied by abnormalities of erythrocyte Na+/K+-ATPase and Na+/Li+ countertransport which are corrected by chronic hydrochlorothiazide administration. These changes could model alterations in renal tubular transport mechanisms still to be elucidated. Chronic thiazide treatment also has a positive effect on bone mineral density.
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PMID:Sodium transport and bone mineral density in hypercalciuria with thiazide treatment. 950 64

Ischemic renal injury is associated with increased fractional excretion of sodium, suggesting a Na+ reabsorption deficiency in renal tubules. To determine whether alterations in expression of the major Na+ transporter genes might contribute to the natriuresis that follows ischemic acute renal failure, the expression of these genes was analyzed in renal cortex and medulla after ischemic-reperfusion injury. Rats were subjected to 30 min of renal pedicle clamping and then sacrificed at 12, 24, or 48 h after reperfusion. Serum creatinine increased significantly at 12 and 24 h, indicative of acute renal failure, but decreased substantially by 48 h. mRNA levels for the NHE-3 Na/H exchanger of the proximal tubule, the apical Na-K-2Cl cotransporter of the thick ascending limb of Henle, the Na-Cl cotransporter of the distal convoluted tubule, the epithelial Na+ channel of the collecting duct, and the basolateral Na(+)-K(+)-ATPase were measured by Northern hybridization. NHE-3 mRNA decreased by approximately 75% at 12 h and remained suppressed at 24 and 48 h after reperfusion. Na-K-2Cl cotransporter mRNA decreased by approximately 88% at 12 h and remained suppressed at 24 and 48 h. Na-Cl cotransporter mRNA remained unchanged at 12 h, decreased by approximately 60% at 24 h, and returned to almost control levels at 48 h. mRNA levels for sodium channels (beta subunit) remained unchanged. Na(+)-K(+)-ATPase mRNA in the medulla decreased by approximately 35 to 40% at 12 and 24 h and by 70% at 48 h, whereas in cortex it decreased by only < 15% at 12 or 48 h after reperfusion. These results suggest that sharp reductions in expression of the NHE-3 Na/H exchanger and the apical Na-K-2Cl cotransporter are major factors in the natriuresis/diuresis that is one of the hallmarks of ischemic acute renal failure. Lasting suppression of these transporters, despite improvement in renal function, could contribute to the deranged NaCl and water excretion that often leads to volume depletion during recovery from ischemic acute renal failure.
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PMID:A possible molecular basis of natriuresis during ischemic-reperfusion injury in the kidney. 955 63

This review describes the supposed mechanisms leading to idiopathic hypercalciuria (IHU) in childhood, further the diagnostic criteria and the proposed treatment modalities are discussed. IHU is not only one of the main causes of renal stone disease in children but it's also at the origin of the postglomerular haematuria and the frequency-dysuria syndrome. Its role in the development of osteoporosis in adults is also documented. The diagnosis of raised calcium excretion is based on age specific values during early infancy. In older children and adults a urinary calcium/creatinine ratio exceeding 0.6 mmol/mmol is regarded as elevated. Dietary calcium restriction can no longer be recommended for the treatment of IHU because it results in secondary hyperoxaluria and on the long-term causes decreased bone mineral density. Patients should be kept on dietary sodium restriction and high fluid intake. In cases IHU associated with recurrent episodes of macroscopic haematuria or recurrent stone disease a therapeutic trial with hydrochlorothiazide in the dose of 0.5-1 mg/kg/day with potassium-citrate supplementation and possibly magnesium citrate should be started. In some special forms of hypercalciuria such as the X-linked recessive nephrolithiasis syndrome or Bartter syndrome the localization and in some cases even the molecular mechanism of the events leading to increased calcium excretion are elucidated. In IHU enhanced Ca(++)-ATPase, and Na-Li countertransport activity and decreased Na+/K+ ATPase activity were described in the erythrocyte membrane model. It is expected that with the molecular genetic development the clinical classification of the hypercalciuric syndromes will become a rational genome-based one.
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PMID:[Idiopathic hypercalciuria in childhood]. 987

This study was undertaken to determine whether reactive oxygen species (ROS) are involved in the pathogenesis of ischemic acute renal failure (IARF) in rabbits. Renal ischemia was induced by clamping bilateral renal arteries for 60 min. Animals were pretreated with combination of xanthine oxidase inhibitor (allopurinol), hydrogen peroxide scavenger (catalase), and hydroxyl radical scavenger (sodium benzoate). Serum creatinine level significantly increased 24 h after ischemia and remained higher to 72 h. Ischemia caused a reduction of GFR and an increase of FENa. Such changes were significantly attenuated by scavenger pretreatment. The uptake of p-aminohippurate in cortical slices and microsomal Na(+)-K(+)-ATPase activity were depressed in kidneys subjected to 72 h of reflow following ischemia, indicating impairment of tubular transport function, which were significantly attenuated by scavenger treatment. Renal blood flow 72 h after reflow was markedly reduced and it was restored by scavenger pretreatment. When animals were pretreated with a potent antioxidant DPPD, lipid peroxidation in cortex and medulla was significantly inhibited. However, ischemia-induced impairment of renal function was not attenuated by pretreatment of the antioxidant. These results suggest that radical scavengers may exert a protective effect against ischemia acute renal failure by other actions rather than ROS scavenging. Thus, the data do not support involvement of ROS in IARF in rabbits.
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PMID:Effects of radical scavengers and antioxidant on ischemic acute renal failure in rabbits. 1004 13

Repetitive brief ischemic episodes (ischemic preconditioning, PC) result in transient intracellular acidosis and protect the heart from subsequent ischemic injury, potentially through a protein kinase C (PKC)-dependent mechanism. We hypothesized that repetitive brief acidification of the heart without concomitant ischemia would also protect the heart from ischemic injury via a PKC-dependent mechanism. Isolated rat hearts underwent 30 min of global ischemia following control perfusion (CTL), or after PC or repetitive acidosis (RA), in the presence of absence of chelerythrine, a specific PKC inhibitor. Intracellular pH, PCr and ATP were measured using 31P NMR spectroscopy, while intracellular sodium [Na]i was measured using 23Na spectroscopy. Na,K-ATPase activity was measured prior to ischemia and on reperfusion. Both PC and RA resulted in transient acidification prior to ischemia. Ischemic injury, as assessed by creatinine kinase (CK) release on reperfusion, was reduced in both the PC and RA hearts [63+/-14 and 16+/-4 IU/g dry weight (dw) respectively, v 705+/-72 IU/gdw for control P<0.001], and was associated with improved functional recovery on reperfusion. PC and RA each significantly reduced Na,K-ATPase activity prior to ischemia (8.18+/-0.47 and 7.76+/-0.54 micromol ADP/h/mg protein) when compared to control (11.05+/-0.54 micromol ADP/h/mg protein P<0.05), limited the rate of ATP depletion during ischemia, and resulted in more rapid normalization of [Na]i on reperfusion. Chelerythrine resulted in intermediate CK release in PC and RA hearts (443+/-48 and 375+/-72 IU/gdw, P<0.001 v PC, P<0.01 v control), but did not alter the rate of ATP depletion or [Na]i kinetics in either PC or RA hearts. PC and RA each protect the ischemic heart, having in common ATP preservation during ischemia and more rapid normalization of [Na]i on reperfusion. These effects, not modulated by protein kinase C, are consistent with the hypothesis that ATP preservation during ischemia provides enhanced substrate for sodium efflux via the Na,K-ATPase on reperfusion.
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PMID:Repetitive acidosis protects the ischemic heart: implications for mechanisms in preconditioned hearts. 1032 17


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