Thiouracil and Mammary Growth

Abstract

Thiouracil admn. to castrated male rats resulted in an increased mammary responsiveness to estrogenic stimulation. In male mice, however, no difference in the mammary response to estrogen could be detected as a result of thiouracil treatment. The results appear to conform with previous reports in the literature which indicate that the mouse and the rat respond differently to experimentally induced hypothyroidism and hyperthyroidism, as regards mammary gland growth and responsiveness. The results are discussed in the light of a possible difference in the relative thyroxin secretion rates of the mouse and rat.