Abstract
Purpose To test the acute effect of estrogen on peripheral blood flow and vascular resistance in postmenopausal women.
PATIENTS AND
Methods Eleven normotensive, post-menopausal female volunteers (mean age 53 +/- 6 years) were studied. Six women were in natural menopause and 5 had had a hysterectomy (mean age of the menopause 49 +/- 3 years). We used a double-blind, randomized protocol to assess the acute response to sublingual estradiol-17 beta (1 mg) on the forearm resistance vessels, compared with sublingual placebo. Blood flow was measured by strain-gauge plethysmography, and mean peripheral vascular resistance was then calculated. Mean blood pressure was also measured.
Results The mean blood flow induced by estradiol-17 beta after 40 minutes was significantly greater than that induced by placebo (3.9 +/- 0.5 mL/100 mL per minute versus 2.4 +/- 0.4 mL/100 mL per minute, respectively, P < 0.05). The forearm resistance was significantly reduced at 40 minutes after estradiol-17 beta compared with placebo (25.7 +/- 4.4 resistance units (RU) to 44.4 +/- 6.4 RU, respectively, P < 0.05). Mean blood pressure 40 minutes after the administration of estradiol-17 beta was no different when compared with placebo (91 +/- 1.5 mm Hg versus 90 +/- 2.5 mm Hg, respectively, P = NS).
Conclusions These results indicate that the acute administration of estradiol-17 beta affects blood flow in the peripheral vasculature in human subjects. The mechanism of this effect has not been determined, but it may explain some of the beneficial effects of estrogen on the vascular system and have future therapeutic potential in postmenopausal women.
estrogen effect peripheral blood flow postmenopausal women, sublingual estradiol-17 beta vascular resistance, acute estrogen administration forearm blood flow, postmenopausal estrogen cardiovascular benefit mechanism, strain gauge plethysmography estradiol vascular study, estrogen vasodilation peripheral vasculature human subjects, hormone replacement therapy vascular resistance double blind, postmenopausal women blood pressure estradiol placebo, Volterrani Rosano Collins estrogen blood flow, estradiol forearm resistance units postmenopause
PMID 7625415 7625415 DOI 10.1016/s0002-9343(99)80130-2 10.1016/s0002-9343(99)80130-2
Keywords
Administration, Sublingual, Blood Flow Velocity/physiology, Double-Blind Method, Estradiol/administration & Dosage/physiology, Female, Forearm/blood Supply, Humans, Middle Aged, Postmenopause/physiology, Reference Values, Vascular Resistance/physiology, Estradiol