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:2.6.1.1 (aspartate aminotransferase)
21,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A protective effect of metipranolol on renal ischemia has recently been demonstrated in our laboratory. The aim of present work was to investigate the effect of this drug on a model of total hepatic ischemia. Inosine was chosen as a comparative agent. Metipranolol (1 mg.kg-1) or inosine (160 mg.kg-1) were given i.v. to rats 15 min prior to inducing of 30-min lasting hepatic ischemia. The animals were followed up for 90 min after the end of ischemia. Pretreatment with inosine almost removed the harmful effect of ischemia on bile flow. Pretreatment with metipranolol slightly minimized the post-ischemic bile flow fall, this effect having been statistically significant only at 30. min of postischemic period. Neither inosine, nor metipranolol administration influenced significantly the ALT or AST plasma activity 90 min after release of hepatic vessels occlusion.
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PMID:The effect of metipranolol and inosine on total hepatic ischemia of rats in vivo. 790 75

This study evaluated the effects of dehydroepiandrosterone (DHEA) on the oxidant [malondialdehyde (MDA)] and antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and glutathione (GSH)] systems in liver after renal ischemia-reperfusion (IR) injury in rabbits. Thirty rabbits were randomly assigned to 3 groups of 10: group I (sham operation), group II (renal IR group), and group III (DHEA, 25 mg/kg, s.c., 15 min pre-ischemia). Renal IR injury in group II caused a decrease of SOD (25%), GPx (36%), and CAT (26%) activities and GSH levels (32%), and increases of MDA (30%) in liver and of ALT and AST activities in serum, compared to group I. DHEA administration decreased the hepatic MDA level (19%) and serum ALT activity (30%) (p <0.01 and p <0.05, respectively), and considerably increased hepatic GSH levels and GPx activities (p <0.01 for both) in group III, compared to group II. These results suggest that DHEA treatment has beneficial effects on antioxidant defenses against hepatic injury after renal IR in rabbits, possibly by augmenting GSH levels and lowering MDA production.
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PMID:Dehydroepiandrosterone improves hepatic antioxidant systems after renal ischemia-reperfusion injury in rabbits. 1458 61

The role of 5-lipoxygenase (5-LOX) in the pathophysiology of renal ischemia/reperfusion (I/R) injury is not known. Here we investigate the effects of 1) the 5-LOX inhibitor zileuton and 2) 5-LOX gene knockout (5-LOX(-/-)) mice on renal dysfunction and injury caused by I/R of the kidney in mice. Wild-type mice treated with zileuton (3 mg/kg i.v.) or 5-LOX(-/-) mice were subjected to bilateral renal artery occlusion (30 min) followed by reperfusion (24 h). Plasma urea, creatinine, and aspartate aminotransferase (AST) were measured as markers of renal dysfunction and reperfusion injury. Kidneys were used for histological evaluation of renal injury. Renal myeloperoxidase activity was measured and used as an indicator of polymorphonuclear leukocyte (PMN) infiltration and renal expression of intercellular adhesion molecule-1 (ICAM-1) was determined using immunohistochemistry. Administration of zileuton before I/R significantly reduced the degree of renal dysfunction (urea, creatinine) and injury (AST, histology). In addition, zileuton reduced the expression of ICAM-1 and the associated PMN infiltration caused by I/R of the mouse kidney. Compared with wild-type mice, the degree of renal dysfunction, injury, and inflammation caused by I/R in 5-LOX(-/-) mice was also significantly reduced, confirming the pathophysiological role of 5-LOX in the development of renal I/R injury. We propose that 1) endogenous 5-LOX metabolites enhance the degree of renal injury, dysfunction, and inflammation caused by I/R of the kidney by promoting the expression of adhesion molecules, and 2) inhibitors of 5-LOX may be useful in the treatment of conditions associated with I/R of the kidney.
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PMID:Reduction of renal ischemia-reperfusion injury in 5-lipoxygenase knockout mice and by the 5-lipoxygenase inhibitor zileuton. 1526 12

The role of poly(ADP-ribose) (PAR) glycohydrolase (PARG) in the pathophysiology of renal ischemia/reperfusion (I/R) injury is not known. Poly(ADP-ribosyl)ation is rapidly stimulated in cells after DNA damage caused by the generation of reactive oxygen and nitrogen species during I/R. Continuous or excessive activation of poly(ADP-ribose) polymerase-1 produces extended chains of ADP-ribose on nuclear proteins and results in a substantial depletion of intracellular NAD(+) and subsequently, ATP, leading to cellular dysfunction and, ultimately, cell death. The key enzyme involved in polymer turnover is PARG, which possesses mainly exoglycosidase activity but can remove olig(ADP-ribose) fragments via endoglycosidic cleavage. Thus, the aim of this study was to investigate whether the absence of PARG(110) reduced the renal dysfunction, injury, and inflammation caused by I/R of the mouse kidney. Here, the renal dysfunction and injury caused by I/R (bilateral renal artery occlusion [30 min] followed by reperfusion [24 h]) in mice lacking PARG(110), the major nuclear isoform of PARG, was investigated. The following markers of renal dysfunction and injury were measured: Plasma urea, creatinine, aspartate aminotransferase, and histology. The following markers of inflammation were also measured: Myeloperoxidase activity, malondialdehyde levels, and plasma nitrite/nitrate. The degree of renal injury and dysfunction caused by I/R was significantly reduced in PARG(110)-deficient mice when compared with their wild-type littermates, and there were no differences in any of the biochemical parameters measured between sham-operated PARG(110)(-/-) mice and sham-operated wild-type littermates. Thus, it is proposed that endogenous PARG(110) plays a pivotal role in the pathophysiology of I/R injury of the kidney.
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PMID:Mice lacking the 110-kD isoform of poly(ADP-ribose) glycohydrolase are protected against renal ischemia/reperfusion injury. 1567 8

There is increasing evidence to suggest that reactive oxygen and nitrogen species play a role in the pathogenesis of renal ischemia-reperfusion (I/R) injury. This study was designed to determine the possible protective effects of trapidil treatment against oxidative and nitrosative tissue injury of kidney induced by I/R. A renal I/R injury was induced by a left renal pedicle occlusion by ischemia for 45 minutes, followed by 1 hour of reperfusion with contralateral nephrectomy in I/R and I/R + trapidil groups. Trapidil (8 mg/kg intravenously) was administrated immediately before reperfusion phase. At the end of the reperfusion period, rats were killed. Then, renal tissue samples were taken for biochemical analysis and histopathological evaluation, and blood samples were obtained to determinate serum urea, aspartate aminotransferase (AST), and tumor necrosis factor-alpha (TNF-alpha) levels. Ischemia-reperfusion injury caused significant increases in myeloperoxidase activity and malondialdehyde and 3-nitrotyrosine levels in renal tissue and elevated serum urea, AST, and TNF-alpha levels. In addition, severe deterioration of renal morphology was seen in the I/R group. Trapidil treatment significantly reduced in biochemical parameters, as well as serum urea, AST, and TNF-alpha levels. Furthermore, renal tissue injury was markedly attenuated with trapidil treatment. These data suggest that reactive oxygen species and reactive nitrogen species play a causal role in I/R-induced renal tissue, and trapidil has a renoprotective effect against oxidative and nitrosative kidney damage.
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PMID:Effects of trapidil on renal ischemia-reperfusion injury. 1701 Dec 70

Exogenous lysophosphatidic acid (LPA) has been shown to beneficial in renal ischemia/reperfusion injury, wound healing and colitis. LPA acts via specific G-protein-coupled receptors and also peroxisome proliferator-activated receptor-gamma (PPAR-gamma). However, activation of PPAR-gamma is dependent on the presence of an unsaturated acyl chain. Here we investigate the effects of saturated LPA (18:0) and unsaturated LPA (18:1) on the organ injury associated with endotoxemia and the receptors mediating LPA activity. Male Wistar rats received either lipopolysaccharide (LPS, 6 mg/kg i.v.) or vehicle. The PPAR-gamma antagonist GW9662 (1 mg/kg i.v.), the LPA receptor antagonist Ki16425 (0.5 mg/kg i.v.) or vehicle was administered 30 min after LPS. LPA 18:0 or LPA 18:1 (1 mg/kg i.v.) or vehicle was administered 1 h after injection of LPS. Endotoxemia for 6 h resulted in an increase in serum levels of aspartate aminotransferase, alanine aminotransferase and creatine kinase. Therapeutic administration of LPA 18:0 or 18:1 reduced the organ injury caused by LPS. LPA 18:0 also attenuated the increase in plasma IL-1beta caused by LPS. Ki16425, but not GW9662, attenuated the beneficial effects of LPA 18:0, however, Ki16425 and GW9662 attenuated the beneficial effects of 18:1. In conclusion, LPA reduces the organ injury caused by endotoxemia in the rat. Thus, LPA may be useful in the treatment of shock of various aetiologies. The mechanism of action is related to acyl chain saturation, with LPA 18:0 acting via G-protein-coupled receptors and LPA 18:1 acting via G-protein-coupled receptors and PPAR-gamma.
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PMID:Lysophosphatidic acid reduces the organ injury caused by endotoxemia-a role for G-protein-coupled receptors and peroxisome proliferator-activated receptor-gamma. 1717 80

In normal conditions, nitric oxide (NO) is oxidized to the anion nitrite, but in hypoxia, this nitrite may be reduced back to NO by the nitrite reductase action of deoxygenated hemoglobin, acidic disproportionation, or xanthine oxidoreductase (XOR). Herein, is investigated the effects of topical sodium nitrite administration in a rat model of renal ischemia/reperfusion (I/R) injury. Rats were subjected to 60 min of bilateral renal ischemia and 6 h of reperfusion in the absence or presence of sodium nitrite (30 nmol) administered topically 1 min before reperfusion. Serum creatinine, serum aspartate aminotransferase, creatinine clearance, fractional excretion of Na(+), and plasma nitrite/nitrate concentrations were measured. The nitrite-derived NO-generating capacity of renal tissue was determined under acidic and hypoxic conditions by ozone chemiluminescence in homogenates of kidneys that were subjected to sham, ischemia-only, and I/R conditions. Nitrite significantly attenuated renal dysfunction and injury, an effect that was abolished by previous treatment of rats with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazole-1-oxyl-3-oxide (2.5 mumol intravenously 5 min before ischemia and 50 nmol topically 6 min before reperfusion). Renal tissue homogenates produced significant amounts of NO from nitrite, an effect that was attenuated significantly by the xanthine oxidoreductase inhibitor allopurinol. Taken together, these findings demonstrate that topically administered sodium nitrite protects the rat kidney against I/R injury and dysfunction in vivo via the generation, in part, of xanthine oxidoreductase-catalyzed NO production. These observations suggest that nitrite therapy might prove beneficial in protecting kidney function and integrity during periods of I/R such as those encountered in renal transplantation.
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PMID:Nitrite-derived nitric oxide protects the rat kidney against ischemia/reperfusion injury in vivo: role for xanthine oxidoreductase. 1720 21

This study was designed to elucidate the role of peroxisome proliferator-activated receptor (PPAR)-alpha in the development of inflammation after ischemia/reperfusion injury of the kidney. We have evaluated the effects of ischemia/reperfusion on renal dysfunction, injury, and inflammation in wild-type mice or mice in which the gene for PPAR-alpha has been deleted [PPAR-alpha(-/-)] and then treated with the PPAR-alpha agonist fenofibrate. Mice were subjected to bilateral renal ischemia (30 min) and reperfusion (24 h) and received fenofibrate (3 mg/kg i.p.) before reperfusion. Plasma creatinine, urea, and aspartate aminotransferase were all used as indicators of renal dysfunction and injury. Kidneys were used for histological and immunohistochemical analysis and markers of inflammation. Fenofibrate significantly attenuated the degree of renal dysfunction, injury, and inflammation caused by ischemia/reperfusion injury. The degree of renal dysfunction, injury, and inflammation caused by ischemia/reperfusion was also significantly augmented in PPAR-alpha(-/-) mice compared with their wild-type littermates. It is interesting that fenofibrate did not protect PPAR-alpha(-/-) mice against ischemia/reperfusion injury. Therefore, we propose that ligands of PPAR-alpha may be useful in the treatment of renal ischemia/reperfusion injury and that endogenous PPAR-alpha limits the degree of renal dysfunction, injury, and inflammation associated with ischemia/reperfusion injury.
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PMID:Peroxisome proliferator-activated receptor-alpha contributes to the resolution of inflammation after renal ischemia/reperfusion injury. 1899 58

Renal ischemia/reperfusion (I/R) occurs in many clinical scenarios, including trauma, elective surgery, and transplantation. Events initiated by this process can lead to inflammation in the kidneys, culminating in local injury as well as distant organ dysfunction. The objectives of this study were to investigate the changes in the functions of the liver and the regulation of gene expression of cytochrome P450 (CYP) isozymes after renal I/R. Hepatoxocity was assessed by serum alanine aminotransferase (sALT), serum aspartate aminotransferase (sAST) and liver glutathione-S-transferase (GST) activities, liver glutathione (GSH) level, and histopathological examination. Hepatic cytochrome P4503A1 (CYP3A1) and cytochrome P4502E1 (CYP2E1) activities were measured by erythromycin N-demethylase (ERD) and aniline hydroxylase (ANH) activities, respectively. CYP3A1 and CYP2E1 mRNA expression was determined by RT-PCR. Results showed that activities of sALT and sAST were significantly increased, while hepatic CYP3A1and CYP2E1 activities as well as their respective mRNA levels were significantly decreased after renal I/R. Moreover, hepatic tissue congestion, degeneration, and local necrosis were observed in rats after 1, 4, and 8h renal reperfusion following 2h renal ischemia. In conclusion, the present study suggests that renal I/R can cause hepatotoxicity and gene expression down-regulation of CYP isozymes in rats.
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PMID:Hepatotoxicity and gene expression down-regulation of CYP isozymes caused by renal ischemia/reperfusion in the rat. 1923 Jun 30

Renal ischemia/reperfusion (I/R) occurs during shock and transplant procedures, greatly affecting outcome. A definitive treatment has not been found. One of the pathophysiological bases of renal I/R injury is the activation of the transcription factor nuclear factor-kappaB (NF-KappaB). We studied the effects of sulfasalazine (SFZ), a NF-kappaB inhibitor, over renal injury in a bilateral renal I/R model in rats. Ten male Wistar rats were subjected to bilateral renal I/R for 45 min followed by 24 h of reperfusion. Half of these received 100 mg/kg SFZ orally before the induction of I/R, while the others received only saline. Five rats served as sham-operated controls. At the end of the reperfusion period, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), blood urea nitrogen (BUN), P-selectin, tumor necrosis factor-alpha (TNF-alpha), intracellular adhesion molecule-1 (ICAM-1), and endothelin-1 (ET-1) concentrations were determined in serum, and renal samples were taken for histological evaluation. After renal I/R, AST, LDH, BUN, TNF-alpha, ICAM-1, and ET-1 serum levels were significantly increased, and tubules were severely damaged on histological analysis, compared to sham controls. SFZ treatment reduced the AST, LDH, BUN, TNF-alpha, and ET-1 elevations, as well as the tubular damage, induced by renal I/R. Serum ICAM-1 and P-selectin were unchanged. These results show that SFZ has a protective effect over renal IR injury. The modulation of adhesion molecules probably does not play a part in these effects, but TNF-alpha and ET-1 modulation could be partly responsible for the effects we observed.
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PMID:Effect of sulfasalazine on renal ischemia/reperfusion injury in rats. 1992 91


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