Immunohistochemical localization of androgen receptor in the human endometrium, decidua, placenta and pathological conditions of the endometrium

The immunohistochemical localization of the androgen receptor in the human endometrium at various stages of the menstrual cycle and post-menopausal period, in decidua and placenta of early pregnancy, and in several pathological conditions of the endometrium has been investigated. At any phase of the menstrual cycle, both endometrial glandular cells and endometrial stromal cells showed positive nuclear staining. Endometrial stromal cells of the functional layer showed stronger staining than those of the basal layer, but endometrial glandular cells of both layers showed the same staining intensity. There was little staining in myometrium. Even after menopause, endometrial glandular and stromal cells showed the same staining pattern as the basal layer of pre-menopausal endometrium and the staining intensity of endometrial stromal cells was weak. In decidua and placenta of early pregnancy, decidual and trophoblastic cells showed positive staining and there was no staining in the stromal cells of placenta. The expression of the androgen receptor was also detected in adenomyosis, endometriosis and endometrial carcinoma. Although the proliferation and differentiation of endometrium are mediated mainly by oestrogen and progesterone receptors, the androgen receptor may play some role in modulating these changes. These results suggest that it may be involved in both physiological and pathological changes of the endometrium.