Genome and Hormones: Gender Differences in Physiology Selected Contribution: Gender differences in the endothelin-B receptor contribution to basal cutaneous vascular tone in humans

Kellogg, D. L., Jr., Y. Liu, and P. E. Pérgola. Selected Contribution: Gender differences in the endothelin-B receptor contribution to basal cutaneous vascular tone in humans. J Appl Physiol 91: 2407–2411, 2001.—To test whether the contribution of endothelin-B (ET-B) receptors to resting vascular tone differs between genders, we administered the ET-B receptor antagonist BQ-788 into the forearm skin of 11 male and 11 female subjects by intradermal microdialysis. Skin blood flow was measured using laser-Doppler flowmetry at the microdialysis site. The probe was perfused with Ringer solution alone, followed by BQ-788 (150 nM) and finally sodium nitroprusside (28 mM) to effect maximal cutaneous vasodilation. Cutaneous vascular conductance (CVC) was calculated (laser-Doppler flowmetry/mean arterial pressure) and normalized to maximal levels (%max). In male subjects, baseline CVC was (mean 6 SE) 19 6 3%max and increased to 26 6 5%max with BQ-788 (P , 0.05 vs. baseline). In female subjects, baseline CVC was 13 6 1%max and decreased to 10 6 1%max in response to BQ-788. CVC responses to BQ788 differed with gender (P , 0.05); thus the contribution of ET-B receptors to resting cutaneous vascular tone differs between men and women. In men, ET-B receptors mediate tonic vasoconstriction, whereas, in women, ET-B receptors mediate tonic vasodilation.