Am J Physiol Endocrinol Metab. 2013 Aug 6;
Wenner MM, Taylor HS, Stachenfeld NS
Hyperandrogenism and vascular dysfunction often coexist in women with Polycystic Ovary Syndrome (PCOS). We hypothesized that testosterone compromises cutaneous microvascular dilation in women with PCOS via the endothelin-1 ET-B subtype receptor. To control and isolate testosterone effects on microvascular dilation, we administered a gonadotropin releasing hormone antagonist (GnRHant) for 11 days in obese otherwise healthy women [(Controls, 22.0 (4) y, 36.0 (3.2) kg/m(2))] or women with PCOS [23 (4) y, 35.4 (1.3) kg/m2)], adding testosterone (T, 2.5 mg/day) for days 8-11. Using laser Doppler flowmetry and cutaneous microdialysis, we measured changes in skin microcirculatory responsiveness (?CVC) to local heating while perfusing ET-A (BQ-123) and ET-B (BQ-788) receptor antagonists under three experimental conditions: baseline (BL, pre-hormone intervention), GnRHant (day 4 of administration), and T administration. At BL, ET-A receptor inhibition enhanced heat-induced vasodilation in both groups [?CVC Control 2.03 (0.65), PCOS 2.10 (0.25), AU/mmHg, P< 0.05]; ET-B receptor inhibition reduced vasodilation in Controls only [?CVC 0.98 (0.39), 1.41 (0.45) AU/mmHg for Controls, PCOS] compared to saline [?CVC Controls 1.27 (0.48), PCOS 1.31 (0.13) AU/mmHg]. GnRHant enhanced vasodilation in PCOS [saline ?CVC 1.69 (0.23) AU/mmHg vs. BL, P
Wenner MM, Taylor HS, Stachenfeld NS
Hyperandrogenism and vascular dysfunction often coexist in women with Polycystic Ovary Syndrome (PCOS). We hypothesized that testosterone compromises cutaneous microvascular dilation in women with PCOS via the endothelin-1 ET-B subtype receptor. To control and isolate testosterone effects on microvascular dilation, we administered a gonadotropin releasing hormone antagonist (GnRHant) for 11 days in obese otherwise healthy women [(Controls, 22.0 (4) y, 36.0 (3.2) kg/m(2))] or women with PCOS [23 (4) y, 35.4 (1.3) kg/m2)], adding testosterone (T, 2.5 mg/day) for days 8-11. Using laser Doppler flowmetry and cutaneous microdialysis, we measured changes in skin microcirculatory responsiveness (?CVC) to local heating while perfusing ET-A (BQ-123) and ET-B (BQ-788) receptor antagonists under three experimental conditions: baseline (BL, pre-hormone intervention), GnRHant (day 4 of administration), and T administration. At BL, ET-A receptor inhibition enhanced heat-induced vasodilation in both groups [?CVC Control 2.03 (0.65), PCOS 2.10 (0.25), AU/mmHg, P< 0.05]; ET-B receptor inhibition reduced vasodilation in Controls only [?CVC 0.98 (0.39), 1.41 (0.45) AU/mmHg for Controls, PCOS] compared to saline [?CVC Controls 1.27 (0.48), PCOS 1.31 (0.13) AU/mmHg]. GnRHant enhanced vasodilation in PCOS [saline ?CVC 1.69 (0.23) AU/mmHg vs. BL, P
via World Class Bodybuilding Forum http://www.worldclassbodybuilding.com/forums/f225/androgens-influence-microvascular-dilation-in-pcos-through-et-and-et-b-receptors-134287/
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