Abstract: | In a sensitive strain of Rat (Sprague-Dawley) a deregulation of the secretion of some pituitary hormones was noted in the female during induction of mammary tumors by dimethylbenzanthracene administration. The deregulation occurred quickly and depended on the stage of the estrous cycle. It mainly consists of hyposecretion of gonadotropins. TSH and GH and of hypersecretion of prolactin. |