Premium
Sensory Nerve‐Mediated and Nitric Oxide‐Dependent Vasodilation Is Reduced in Non‐Hispanic Blacks Compared to Non‐Hispanic Whites
Author(s) -
Walker Demetria,
Hollowed Casey,
Miller James,
Otis Jeffrey,
Hayat Matthew,
Quyyumi Arshed,
Wong Brett
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.696.7
Subject(s) - microdialysis , vasodilation , sodium nitroprusside , medicine , nitric oxide , sensory nerve , lidocaine , anesthesia , blood flow , laser doppler velocimetry , microcirculation , sensory system , central nervous system , neuroscience , biology
Reduced microvascular function is recognized in healthy non‐Hispanic Blacks compared to non‐Hispanic Whites, but it is unclear whether sensory nerve function is altered in non‐Hispanic Blacks. Local heating of the skin allows for the simultaneous assessment of both sensory nerve‐mediated and nitric oxide (NO)‐dependent vasodilation. The purpose of this study was to test the hypothesis that the magnitude of cutaneous sensory nerve‐mediated and microvascular endothelial‐dependent vasodilation is reduced in non‐Hispanic Blacks compared to non‐Hispanic Whites. Six healthy participants who self‐identified as non‐Hispanic Black (n=3) or non‐Hispanic White (n=3) were instrumented with two microdialysis fibers on the forearm: 1) lactated Ringer's (control) and 2) topical anesthetic (5% lidocaine) to inhibit sensory nerve function. A rapid local heating protocol was conducted at each microdialysis site where the temperature of the skin was heated from 33°C to 39°C at a rate of 1°C/sec. Skin blood flow was continuously monitored at each site with laser‐Doppler flow (LDF) probes. At the plateau of skin blood flow, 20 mM L‐NAME was perfused at each site to inhibit NO synthase in order to calculate %NO‐dependent vasodilation. Following L‐NAME infusion, maximal skin blood flow was reached by infusing each site with 54 mM sodium nitroprusside and heating the skin to 43°C. Cutaneous vascular conductance (CVC) was calculated (LDF/MAP) and standardized to maximal blood flow (%CVC max ). Data shown are mean ± SD. At control sites, the initial peak (33 ± 9 %CVC max ) and plateau (52 ± 9 %CVC max ) in non‐Hispanic Blacks were reduced compared to non‐Hispanic Whites (53 ± 8 % and 67 ± 10 %CVC max ; P < 0.05 for all conditions). At sites treated with anesthetic, the initial peak was unaltered in non‐Hispanic Blacks (26 ± 10 %CVC max ) but was significantly reduced in non‐Hispanic Whites (23 ± 13 %CVC max ). Anesthetic did not affect the plateau in either non‐Hispanic Blacks (56 ± 5 %CVC max ) or non‐Hispanic Whites (62 ± 4 %CVC max ). Calculated %NO‐dependent vasodilation was reduced in non‐Hispanic Blacks (51 ± 6 %NO) compared to non‐Hispanic Whites (67 ± 8 %NO). These data indicate that sensory nerve function, microvascular function, and NO‐dependent vasodilation are all decreased in non‐Hispanic Blacks in comparison to non‐Hispanic Whites. Support or Funding Information NIH R01HL141205 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .