Abstract
It has become increasingly important during these last few years of intensive experimentation on the hormonal control of the mammary apparatus to discriminate between the respective rôles played by the primary female sex hormone (estrin) and the anterior pituitary mammary-stimulating hormone (mammatropin), in inducing growth and secretory activity of the breast.
Several years ago in the course of experiments on the effects of purified gonadotropic hormone in hypophysectomized rats 1 it was noticed that although the female genital tract responded to the hormones of the stimulated ovaries, the mammary apparatus showed only a poorly-developed duct system. These findings pointed to a greater importance of the anterior pituitary as a source of a mammary growth-promoting factor than is admitted by some investigators. To further determine the degree of mammary stimulation possible through estrin, it was decided to use hypophysectomized male guinea pigs, since Laqueur and others 2 have shown that the intact male guinea pig responds to estrin treatment by mammary growth and lactation. Asdell and Seidenstein 3 found the development of the mammary glands of ovariectomized, hypophysectomized rabbits injected daily for 15 days with 25 rat units of estrin plus 4 rabbit units of progestin almost the same as ovariectomized, non-hypophysectomized rabbits similarly treated. Apparently they did not study the effect of estrin alone.
Get full access to this article
View all access options for this article.