Relation of Mammary Tumors to Mammotropes. H. Hormone Responsiveness of 3-methylcholanthrene Induced Mammary Carcinomas

Abstract

About 72% of primary 3-methlylcholanthrene induced mammary carcinomas were inhibited to varying degrees by ovariectomy and 86% by hypophysectomy. Most inhibited tumors remained minute; a few resumed progressive growth and a moderate number (about 37% in the hypophysectomized series) could not be identified at autopsy. Grafts of functional mammotropic tumors (providing a steady supply of mammotropin) on hypophysectomized animals, whose mammary tumors have markedly decreased in size following ovariectomy or hypophysectomy, caused not only resumption of progressive tumor growth, but also appearance of numerous new mammary tumors. Thus the mammotropic hormones can unfold latent neoplastic potentialities.