Evaluation of in vivo and in vitro responses of endometrial adenocarcinoma to progestins.

Abstract

In vivo effects of progesterone and other progestins on normal human endometrium have been evident histologically since the 1930’s (1,2). Histochemical procedures have been used to demonstrate the influence of these compounds on glycogen accumulation and secretion of proteins and carbohydrates (3). Correlation of changes in enzymatic activities and other biochemical parameters throughout the menstrual cycle have suggested specific effects of progesterone on the endometrium (4). In some cases, these putative effects could be ascertained in vivo by administering progestins to women in the follicular phase of their menstrual cycles and examining endometrial biopsies taken before the onset of the luteal phase. Experiments of this type showed that progestins increase the activity of estradiol 17s dehydrogenase (E2DH) (5) and reduce the levels of estrogen receptors (RE) in the tissue (6). The in vivo effect of progestins on endometrial E2DH activity was also noted when they were administered to postmenopausal women (7).