Endothelium-dependent control of vascular tone in the rabbit kidney after ischemia and reperfusion

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.