Hormonal Influences on Growth and Somatotropic Actions of Autonomous Mammotropes.

Abstract

The role of gonadal, adrenal, and hypophyseal hormones on the growth and somatotropic actions of a transplantable, functional mammotropic pituitary tumor (MtT) was studied in rats. Although this tumor is autonomous it is highly responsive to estrogen, the rate of tumor growth and body growth of the host being roughly proportional to the quantity of estrogen administered. Hormones of mammotropes stimulate body growth and growth of many organs. Somatotropic and mammotropic effects are marked in hypophysectomized rats bearing mammotropic tumors; thus they are independent of other pituitary factors.