Vascular smooth muscle function in rats with acute renal failure.

Vascular smooth muscle function in rats with glycerol-induced acute renal failure (ARF) was investigated by recording both the contractile responses of portal vein segments and the relaxant responses depressed contractile responses to the alpha 1-agonist methoxamine, the alpha 2-agonist B-HT 920 and to the calcium agonist BAY K 8644 when compared with controls. Both isoprenaline and nitroprusside produced 100% reversal of KCl induced tone in control aortic rings but in rings from rats with ARF complete reversal of of tone could not be obtained with either dilator drug. It is suggested that a defect in mitochondrial function and hence energy supply may account for the diminished ability of vascular preparations from rats with ARF to constrict and relax.