Morphometric, immunohistological and three-dimensional evaluation of the endometrium of menopausal women treated by oestrogen and Crinone, a new slow-release vaginal progesterone.

Recently advanced computerized technology was applied to the investigation of morphometric, immunohistological and three-dimensional changes of the endometrial mucosa in order to evaluate quantitatively the effects of three doses of a new slow-release vaginal progesterone on the endometrium in post-menopausal women. A total of 20 menopausal women, deprived of ovarian function, were given oestrogen for 12 days and a combined therapy of oestrogen (administered orally) and progesterone for another 12 day period. Progesterone was administered vaginally through a new gel (Crinone) utilizing a bioadhesive, biocompatible polymer as a base to achieve a sustained release effect. An endometrial biopsy was taken before treatment, after oestrogen-only treatment and after the oestro-progestogen therapy. Before treatment, all the patients exhibited an atrophic endometrium. After oestrogen-only treatment, typical proliferative changes occurred: an increase in the endometrium thickness, an increase in the mitotic index, numerous cylinder-like glands and no coiled glands, and high concentrations of oestrogen receptors (ER) and progesterone receptors (PR). After the oestro-progestogen therapy, whatever the dose of progesterone given, a secretory transformation of the endometrial mucosa occurred, mitotic activity decreased significantly, more ramified and coiled glands were observed, and a decrease in PR content was noted in epithelial and stromal nuclei, and a decrease in PR content was also observed in epithelial nuclei but not in stromal nuclei. Accurate new techniques of image analysis have shown that crinone therapy could eliminate the proliferative effects of oestrogen treatment in post-menopausal women, despite doses as low as 45 mg of progesterone administered vaginally every other day. The results suggest that the sustained release effects of Crinone are clinically relevant.