Endogenous estrogen and acetylcholine-induced vasodilation in normotensive women

Abstract

Acute exogenous estrogen administration enhances endothelial function in postmenopausal women. To evaluate the effect of endogenous estrogen on endothelium-dependent vasodilation, in 10 fertile normotensive women (age range 45 to 51 years) we studied the changes in forearm blood flow (strain- gauge plethysmography) induced by intrabrachial acetylcholine (0.15, 0.45, 1.5, 4.5, 15 μg · 100 mL-1 · min-1), an endothelium-dependent vasodilator, or sodium nitroprusside (1, 2, 4 μg · 100 mL-1 · min-1), an endothelium-independent vasodilator, in basal conditions and within 1 month after ovariectomy. As control subjects, 10 matched healthy women were also evaluated. In basal condition, vasodilation to acetylcholine and sodium nitroprusside was similar in patients and control subjects. Ovariectomy was followed by endogenous estrogen deprivation (from 71.6±31.3 to <12 pg/mL) and was associated with a significant (P