THE PHYSIOLOGICAL FRACTIONATION OF PITUITARY GONADOTROPIC FACTORS CORRELATED WITH CYTOLOGICAL CHANGES1

Abstract

Removal of estrogen or androgen influence by gonadectomy and the controlled administration of gonadal steroids resulted in regulation of the concentration of follicle stimulating (FSH) and lutcinizing (LH) factors in pituitary glands of young adult rats. These physiological changes were correlated with cytological findings. Gonadectomy in both sexes results in a marked increase in both LH and FSH in the pituitary as well as a corresponding increase in the red and purple (PAS-Methyl blue staining) pituitary gonadotropes. The administration of the equivalent of 3 μg. of estradiol benzoate per day over a 45-day period stimulates depletion of LH. FSH is also markedly decreased. The cytological picture shows very few red but some purple gonadotropes. On the other hand, the administration of the equivalent of 3 mg. of testosterone propionate per day over a 45-day period also depletes the LH but the FSH content remains high and the correlated cytological findings show a corresponding decrease in the red gonadotropes, but with little effect on the purple ones. These findings show that FSH and LH can be differentiated by physiological means and support the concept that the red gonadotropic cells are related to LH production or storage, and the purple ones to FSH production or storage.