IMMUNOHISTOCHEMICAL DISTRIBUTION OF PROGESTERONE, ANDROGEN AND ESTROGEN-RECEPTORS IN THE HUMAN OVARY DURING THE MENSTRUAL-CYCLE - RELATIONSHIP TO EXPRESSION OF STEROIDOGENIC ENZYMES

In order to characterize immunohistochemically the possible in-situ effects of gonadal steroid hormones in the human ovary during the menstrual cycle, we immunolocalized progesterone (PR), androgen (AR) and oestrogen (ER) receptors in 50 normal cycling human ovaries, and examined the relationship between these findings and the cellular localization of steroidogenic enzymes including cytochrome P450 cholesterol side-chain cleavage (P-450scc) enzyme, 3 beta-hydroxysteroid dehydrogenase (3 beta HSD), cytochrome P450 17 alpha-hydroxylase (P-450c17) and cytochrome P-450 aromatase (P-450arom). A large number of stromal cells were positive for AR, regardless of the distance from a follicle. No steroidogenic enzymes were observed in the stromal cells. In the pre-antral follicle, AR was observed in the theca cells. F450scc, 3 beta HSD and P-450c17 were sporadically expressed in the theca cells in relatively large-sized pre-antral follicles. ER was positive in the granulosa cells only in the P-450arom-positive antral or pre-ovulatory follicle, which is likely to be a selected follicle. In the corpus luteum, in the period from ovulation to the midsecretory phase, PR immunoreactivity was observed in a large number of both the luteinized granulosa and the theca cells. All steroidogenic enzymes were observed in all corpora lutea, but ER was negative in any corpus luteum. In the atretic follicle, AR was present in the theca interna cells. P-450scc, 3 beta HSD and P-450c17 were observed in the theca interna cells in some atretic follicles. These immunohistochemical findings demonstrated that steroid hormones locally produced may have important roles, as local regulators, in the human ovary during the menstrual cycle.