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Uterine receptor for oxytocin: Effects of estrogen

1975; Elsevier BV; Volume: 65; Issue: 1 Linguagem: Inglês

10.1016/s0006-291x(75)80080-5

1090-2104

Melvyn S. Soloff,

Stress Responses and Cortisol

The effect of estrogen treatment on the affinity and concentration of uterine binding sites for oxytocin was studied. The oxytocin receptor was present in the uterus of the ovariectomized rat but the affinity for oxytocin increased more than four-fold 24 hr after a single injection of diethylstilbestrol. An increase in affinity was apparent 6 hr after estrogen. An increase in the number of oxytocin binding sites per uterus was apparent only 12 hr after estrogen, reaching twice the initial value by 24 hr. These results suggest that the enhanced sensitivity of the rat uterus to oxytocin following estrogen treatment is the result of an increase in the affinity and number of oxytocin receptors in the uterus. The affinity of uterine binding sites for (lysine)vasopressin was less than for oxytocin, whether or not the rats were treated with estrogen.