BRADYKININ-INDUCED VENODILATION IS NOT DIFFERENT IN BLACKS

Aims The aim of this study was to determine whether young, normotensiv e blacks who have been recently demonstrated to have a venodilator res ponse to isoprenaline decreased compared with whites, also have an dec reased vasodilatory response to bradykinin. Methods Eleven black and 1 1 white subjects were studied. Full dose-response curves to bradykinin (dosing range 0.5-500 ng min) were generated in hand veins preconstri cted with phenylephrine (dosing range 20-6800 ng min(-1)). Results The groups had a similar maximal response to bradykinin (57.6 +/- 32.2% v s 67.8 +/- 49.3%, P = NS 95% confidence interval for the difference (C I): -47.3, 26.8). Also, the log of the dose that produced half maximal response to bradykinin was similar for the two groups (0.89 +/- 0.58 vs 0.78 +/- 0.61 ng min(-1), P = NS, 95% CI: -0.42, 0.64). There was n o difference between the two groups in the log dose of phenylephrine n ecessary to produce 80% constriction of the hand vein. Conclusion Dimi nished vasodilatory response to endothelium-derived relaxing factor (E DRF) does not seem to be associated with the increased prevalence of h ypertension in blacks.