Pheromone-induced changes in the acidophil concentration of mouse pituitary glands.

Pituitaries of female mice in anestrus resulting from colony housing were characterized by a 58.0-percent (acidophil content. Subsequent exposure to restrained male mice for one and two nights failed to evoke significant acidophilic degranulation and resulted in pituitary acidophil values of 57.4 and 55.1 percent respectively. Exposure to released males on the third night produced marked acidophilic degranulation resulting in a significant decline in pituitary acidophils to 38.0 percent. These findings support the view that female pheromone suppresses and male pheromone favors the secretion of follicle-stimulating hormone and indicate that luteotrophic hormone is secreted at its assigned time in the sequence of cyclic ovarian events initiated by the secretion of follicle-stimulating hormone.