Enalaprilat-Mediated Activation of Kinin B1 Receptors and Vasodilation in the Rat Isolated Perfused Kidney

The present study evaluated whether enalaprilat (the active form of enalapril, an angiotensin-converting enzyme inhibitor) activates B-1 receptors. We observed that the levels of B-1 receptor mRNA and protein expression were upregulated in the kidneys of diabetic rats. Bradykinin (BK)-induced renal vasodilation decreased in isolated perfused kidneys of diabetic rats, but des-Arg(9)-BK-induced renal vasodilation increased. Enalaprilat also produced vasodilation in the isolated perfused kidneys of control and diabetic rats. The response to des-Arg(9)-BK or enalaprilat was blocked by Lys-(des-Arg(9), Leu(8))-BK (a B-1 receptor antagonist) and N-nitro-L-arginine methyl ester (an inhibitor of nitric oxide synthase). These results suggest that enalaprilat activates B-1 receptors and stimulates the production of nitric oxide in the kidneys of both control and diabetic rats. Copyright (C) 2011 S. Karger AG, Basel