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Androgen effects on in vitro and in vivo coronary vasomotor responses in intact and castrated swine
Author(s) -
O'Connor Erin Kathleen,
Ivey Jan R,
Bowles Douglas K
Publication year - 2010
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.24.1_supplement.1034.4
Subject(s) - androgen , medicine , vasomotor , endocrinology , dihydrotestosterone , testosterone (patch) , in vivo , endogeny , coronary circulation , blood flow , biology , hormone , microbiology and biotechnology
Low endogenous testosterone levels have previously been shown to be a risk factor for the development of coronary artery disease; however, the effects of endogenous testosterone levels on the acute coronary vasomotor responses to androgen administration are not clear. The objective of this study was to compare the effects of acute androgen administration on in vivo coronary blood flow and in vitro coronary microvascular diameter in intact and castrated adult male swine. Pigs were anesthetized and received intracoronary infusions of physiologic levels (1–100 nM) of testosterone (T), the epimer epitestosterone (EpiT), and the metabolite 5 alpha‐dihydrotestosterone (DHT) while left anterior descending coronary blood flow and mean arterial pressure were continuously monitored. Following sacrifice, coronary arterioles were isolated, cannulated, and exposed to physiologic concentrations (1–100 nM) of T, EpiT, and DHT. In vivo, T, EpiT, and DHT produced greater increases in coronary conductance in the intact compared to the castrated males. Similarly, in vitro , percent maximal dilation of microvessels was greater in the intact compared to the castrated males for T, EpiT, and DHT. In conclusion, increases in coronary blood flow and coronary arteriolar relaxation in response to acute androgen administration are influenced by endogenous androgen status. Supported by NIH HL071574.