THE FOLLICLE-STIMULATING HORMONE-CONTENT OF THE HYPOPHYSIS OF THE RAT AS INFLUENCED BY GONADECTOMY AND OESTROGEN TREATMENT

Abstract

The pituitary follicle stimulating hormone (FSH) content of adult intact and gonad-ectomized, estrogen and oil treated, female and male rats was determined by injecting hypophyseal extracts into hypophysectomized hemicastrated immature male recipient rats treated with an overdose of interstitial-cell stimulating hormone (ICSH) and recording the weight increase of the testes. Ovariectomy caused the FSH content of the female rat hypophysis to increase more than the ICSH hormone content. FSH content of the intact male hypophysis was more than 5 times higher than that of the female; gonadectomy did not produce a conspicuous increase. Oestradiol benzoate (50 [mu]g daily) was unable to diminish the already low FSH content of the hypophysis of the intact female, but was able to lower the high content in spayed females, intact males, and castrated males to a strikingly similar level, which was, however, not as low as that in the intact female. The growth inhibiting effect of estrogen was greater in spayed females than in intact females, as was the pituitary-enlarging effect.