Soy isoflavones enhance coronary vascular reactivity in atherosclerotic female macaques.
OBJECTIVE
To examine the effects of soy phytoestrogens on coronary vascular reactivity in atherosclerotic male and female rhesus monkeys.


METHODS
A prospective, randomized, blinded, controlled study.


METHODS
Comparative Medicine Clinical Research Center of an academic medical center.


METHODS
Twenty-two young adult rhesus monkeys with pre-existing diet-induced atherosclerosis.


METHODS
Monkeys were fed soy-based diets for 6 months identical in composition, except that the isoflavones were extracted from one flow-isoflavone) and intact in the other (high-isoflavone). Quantitative coronary angiography was performed at the end of the study period. Females in the low-isoflavone group under went a second angiography after an acute IV dose of genistein.


METHODS
Percent change in diameter of the proximal left circumflex coronary artery in response to intracoronary acetylcholine and nitroglycerin, compared with control diameter.


RESULTS
Arteries from males constricted in response to acetylcholine. Arteries from females in the low-isoflavone group constricted (-6.2% +/- 2.8%, mean +/- SEM), whereas arteries from females in the high-isoflavone group dilated (6.4% +/- 1.2%, mean +/- SEM). Intravenous administration of genistein caused dilation in the previously constricting low-isoflavone females (3.3% +/- 2.8%).


CONCLUSIONS
Like mammalian estrogens, dietary soy isoflavones enhance the dilator response to acetylcholine of atherosclerotic arteries in female monkeys.
Honoré
E K
EK
Comparative Medicine Clinical Research Center, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina.
Williams
J K
JK
Anthony
M S
MS
Clarkson
T B
TB
D000818:Animals; D001161:Arteriosclerosis / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects* / Q000503:physiopathology; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D005260:Female; D019833:Genistein; D007529:Isoflavones / Q000494:pharmacology*; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008253:Macaca mulatta; D008297:Male; D014661:Vasoconstriction / Q000187:drug effects
D004968:Estrogens, Non-Steroidal; D007529:Isoflavones; D008055:Lipids; D008074:Lipoproteins; C004742:daidzein; D019833:Genistein