The Effect of Hypophysectomy upon Corticosterone-Induced Ovulation in the Hen (Gallus domesticus)

Abstract

When the ovary of a laying hen contains a mature follicle, ovulation can be induced by an injection of corticosterone. The dose which is required to consistently induce a premature ovulation causes the plasma concentration of corticosterone in the peripheral blood to rise to levels which are higher than those normally observed during the ovulation cycle. The accompanying rise and fall in progesterone secretion is normal. Hypophysectomy prevents both ovulation and the secretion of progesterone which follows an injection of corticosterone. It was concluded that the injection of corticosterone triggers a sequence of events which requires the participation of the pituitary gland for both ovulation and progesterone secretion to occur.