Cutaneous sensory nerve ‐mediated microvascular vasodilation in normotensive and prehypertensive non‐Hispanic Blacks and Whites

Cutaneous sensory nerve activation is shifted to a higher temperature threshold in non ‐Hispanic Blacks relative to non‐Hispanic Whites. Administration of exogenous nitric oxide via nitroprusside lowered the temperature threshold in non‐Hispanic Blacks but not in non‐Hispanic Whites. AbstractRelative to non ‐Hispanic Whites, non‐Hispanic Blacks are disproportionately affected by elevated blood pressure (BP). It is unknown whether race or subclinical increases in BP affect the ability of cutaneous sensory nerves to induce cutaneous microvascular vasodilation. Sixteen participants who self‐identifi ed as non‐Hispanic Black (n = 8) or non‐Hispanic White (n = 8) were subgrouped as normotensive or prehypertensive. Participants were instrumented with three intradermal microdialysis fibers: (a) control, (b) 1 μM sodium nitroprusside (SNP), an exogenous nitric oxide (NO) donor, and (c) 20 mM NG‐nitro‐l‐arginine methyl ester (L‐NAME), a non‐selective NO synthase inhibitor. A slow local heating protocol (33–40°C, 0.1°C/min) was used to assess the onset of cutaneous sensory nerve‐mediated vasodilation (temperature threshold) and skin blood flow was measured using laser‐Doppler flowmetr y. At control sites, the temperature threshold occurred at a higher temperature in non‐Hispanic Blacks (normotensive: 37.2 ± 0.6°C, prehypertensive: 38.9 ± 0.5°C) compared to non‐Hispanic Whites (normotensive: 35.2 ± 0.8°C, prehypertensive: 35.2 ...

Source: Physiological Reports - May 12, 2020 Category: Physiology Authors: Casey G. Turner, James T. Miller, Jeffrey S. Otis, Matthew J. Hayat, Arshed A. Quyyumi, Brett J. Wong Tags: ORIGINAL RESEARCH Source Type: research