Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0920646 (renal ischemia)
 2,515 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Whole blood and plasma serotonin (5-HT), its major metabolite--5-hydroxyindoleacetic acid (5-HIAA), renal cortical blood flow, serum creatinine and whole blood cyclosporine A (CyA) levels were investigated in rats administered with CyA at a dose of 5 mg/kg b.w. or 10 mg/kg b.w. for 14 consecutive days. Serum creatinine remained unaltered during CyA treatment and no apparent changes in excised kidneys were found. Dose-dependent increases in whole blood and plasma 5-HT as well as whole blood 5-HIAA levels were observed. Renal cortical blood flow declined significantly and correlated inversely with whole blood 5-HT and 5-HIAA as well as with plasma 5-HT. Whole blood 5-HT was positively related to whole blood CyA levels. Taking all these data into account and considering the fact that 5-HT is a potent vasoconstrictor, a possible role of this amine in the pathogenesis of renal ischemia during CyA administration is suggested.
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PMID:Serotonergic measures in cyclosporine A treated rats. 753 26

We investigated the effects of renal ischemia with reperfusion on the reactivity of rabbit renal vasculature. The main renal and arcuate arteries were isolated and studied as ring preparations. In the renal artery, concentration-response curves for potassium chloride (KCl), noradrenaline (NA), serotonin (5-HT), angiotensin II (AII), acetylcholine (ACh), A23187 or sodium nitroprusside (SNP) were unaltered after ischemia and reperfusion. Under the same conditions, the relaxation of arcuate arteries elicited by ACh was reduced when vessels were precontracted with methoxamine but not with KCl, whereas SNP-induced responses were unaffected. In anesthetized rabbits, renal blood flow and corresponding renal vascular resistances (RVR) were not modified by ischemia and reperfusion. ACh (1, 3 and 10 micrograms/kg per min) reduced RVR (maximally -24 +/- 8%) and this response was unchanged after ischemia and reperfusion (maximally -25 +/- 10%). These results demonstrate that the rabbit renal vasculature is relatively resistant to an ischemic insult and is probably not involved in the development of postischemic renal failure.
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PMID:Endothelium-dependent control of vascular tone in the rabbit kidney after ischemia and reperfusion. 845 77

The influence of ketanserin, a S2-serotonergic receptor blocker, on the impaired renal hemodynamics in a clamp model of renal ischemia in rats was investigated in this study. Serotonin-induced vasoconstriction of the renal vascular bed was augmented after ischemia. This constriction is blocked by ketanserin (0.05 mg/kg i.v. bolus, followed by 0.1 mg/kg per h infusion). The influence of the same ketanserin treatment on the response of RBF versus a stepwise lowering of the renal perfusion pressure was studied in post-ischemic kidneys with an established loss of autoregulation of RBF. An almost perfect restoration of the autoregulatory response was apparent after the S2-serotonergic antagonism. Despite this beneficial effect on renal hemodynamics, renal function, judged by measurement of GFR and urinary sodium excretion rate, was not influenced by an acute infusion of ketanserin in post-ischemic kidneys. It is suggested that serotonin plays a pivotal role in the suppression of autoregulation of RBF by a S2-serotonergic receptor-mediated vasoconstrictor effect in the post-ischemic kidney. It most likely masks the potential myogenic dilatory response of the smooth muscle cells in renal preglomerular microvasculature. Restoration of the renal autoregulatory capacity by S2-serotonergic receptor antagonism could be of clinical relevance in human post-ischemic acute renal failure.
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PMID:Beneficial influence of ketanserin on autoregulation of blood flow in post-ischemic kidneys. 872 97

Serotonin is important for effective renal blood flow (RBF) autoregulation in the normal rat and at two or seven days of reperfusion following renal ischemia. It has been suggested that after these reperfusion periods and during renal perfusion pressure (RPP) lowering, the vasodilatory autoregulation mechanism is not damaged but overwhelmed by increased 5-HT2-mediated vasoconstriction, resulting in complete loss of autoregulation. This study analyzes the influence of the 5-HT2-antagonist ketanserin on RBF autoregulation after two hours or one day of renal reperfusion following ischemia and in a model of cyclosporine (20 mg/kg.day for 10 days)-induced nephrotoxicity. Autoregulation was lost both after brief reperfusion periods and after cyclosporine. Similar to the two or seven days of reperfusion experiments, ketanserin in the cyclosporine model led to reappearance of autoregulation down to RPP 95 mm Hg. Despite an increased response to intrarenal serotonin after two hours of reperfusion, autoregulation was not restored by ketanserin. At one day of reperfusion and with ketanserin, autoregulation was present down to 105 mm Hg. Thus, during the early reflow period, other factors (of decreasing importance) most likely add to autoregulation loss.
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PMID:Influence of ketanserin on experimental loss of renal blood flow autoregulation. 973 3