Diverse effects of estradiol-17 beta: concurrent suppression of appetite, blood pressure and vascular reactivity in conscious, unrestrained animals.
Evidence from epidemiological and clinical investigations have suggested a relationship between estrogen-containing oral contraceptives and hypertension. The present series of studies, however, documents the ability of estradiol-17 beta, a natural ovarian estrogen, to lower resting blood pressure and pressor responses to norepinephrine in conscious, unrestrained guinea pigs. Arterial measurements were made of resting blood pressure and heart rate, plus pressor responses to intravenous infusions of 1.56 micrograms norepinephrine. Injection of 30 micrograms estradiol-17 beta reduced resting pressures up to 12% and pressor responses up to 20% in the interval from 12 to 48 hours postinjection. The estradiol treatment also significantly and reversibly lowered food intake, water intake, and body weight. These effects could be induced by either 3 or 30 micrograms of estradiol benzoate for up to 4 days if estradiol treatment was continued. Parallel studies indicated that NE-induced contractions of the isolated aorta were markedly reduced by pretreatment with estradiol. These studies indicate that natural ovarian estrogens may reduce blood pressure by reducing the contractility of the arterial smooth muscle.
McCaffrey
T A
TA
Cornell University Medical College, Division of Hematology/Oncology, New York, NY 10021.
Czaja
J A
JA
D000818:Animals; D001066:Appetite / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D004327:Drinking Behavior / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006168:Guinea Pigs; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010052:Ovariectomy; D013997:Time Factors
D004958:Estradiol; D009638:Norepinephrine