Fluctuations in FSH and LH content of the anterior pituitary of the castrated adult female and puerperal rat.

It has been well established that castration in several animals, especially in rats, is followed by the appearance and the development of the "castration-cell" in the anterior lobe of the pituitary gland. It has also been reported by many investigators that characteristic morphological finding is accompanied with a functional change: a gradual, significant increase in the gonadotrophic potency of the pituitary gland. In the present study, the FSH and LH content of the anterior lobe of the pituitary gland of the adult female rat was assayed simultaneously at approximately weekly intervals after gonadectomy. FSH content was measured by the modified HCG-augmentation method of Steelman-Pohley(1953) and LH content by the modified ovarian ascorbic acid depletion method of Parlow(1961). The special dynamic processes at the end of pregnancy-delivery,puerperium, lactation are important events for the female; especially delivery, when the placenta, the producer of many hormones, is rapidly removed, and the maternal physiology is markedly affected. Post-partum ovulation in rats and other animals is an expression of this hormonal disturbance. This interesting phenomenon