MAMMARY GLAND DEVELOPMENT WITH MAMMOGEN I IN THE CASTRATE AND THE HYPOPHYSECTOMIZED RAT1

Abstract

IN 1936, REECE et al. (1) published the first experiments showing that the mammary glands of completely hypophysectomized animals did not respond to administration of ovarian hormones. Gomez and Turner (2) soon demonstrated that the anterior pituitary gland from pregnant animals or those pretreated with estrogen contained a factor which would cause mammary development in hypophysectomized or normal guinea pigs. It was also demonstrated that thyrotropic, adrenotropic, and lactogenic AP extracts or adrenal cortical extract plus estrogen were ineffective in hypophysectomized guinea pigs. The theory was then advanced by Gome? and Turner (3) that a previously unrecognized pituitary factor or factors were the direct agents of mammary growth. This complex was called mammogen. From earlier observations with ovarian hormones it appeared that there must be two mammogenic factors. The duct growth factor {mammogen I) was thought to be stimulated to increased secretion by estrogen alone and caused mammary duct growth.