Gonadotropin-like Immunoreactivity in the Rat Ovary

Abstract

To devise efficient and safe methods of contraception, it is necessary to gain a firm grasp of the biological processes of reproduction. In the female, the gonadotropic hormones have a central role in regulating the reproductive cycles. Thus, it is of prime importance to understand the effect that these hormones have on their target cells. Labeled gonadotropins have been used in autoradiographic studies of the ovary. The majority of these reports have focused on the cells of the corpus luteum (Espeland et al., 1968; Midgley and Beals, 1971; Ryan and Lee, 1976; Abel et al., 1976; Chen et al., 1978; Conn et al., 1978). Fewer electron-microscopic autoradiographic studies have been reported on the cells of the stratum granulosum (Abel et al., 1976; Han, 1979), and none on the theca interna. Since immunocytochemistry (ICC) has been successfully used to demonstrate gonadotropin immunoreactivity in the male reproductive tract (Hutson et al., 1977; Childs et al., 1978), it was decided to employ this technique at the ultrastructural level to localize immunoreactive gonadotropins in the rat ovary. Three predominant cell types of the ovary, namely, the cells of the corpus luteum, the stratum granulosum, and the theca interna, were studied.