An Intercellular Response to Estrogen by Granulosa Cells in the Rat Ovary; An Electron Microscope Study*

Abstract

ABSTRACT. Ultrastructural responses of ovarian granulosa cells to exogenous estrogen have been investigated in immature rats. Animals, 21-daysold, were hypophysectomized and a regimen of 6 daily injections was initiated 30 hr after the operation. Some rats received sesame oil only and others were given totals of 3 or 6 mg diethylstilbestrol (DES). Ovarian tissues were prepared for microscopy 24 hr after the last injection. In addition, normal rats were sacrificed at 21 days to monitor ovarian morphology at the time of hypophysectomy. Rapid simultaneous changes, occurring in cells of the pre-ovulatory rat follicle, suggest a necessity for cell communication, particularly in the multilayered avascular granulosa. Therefore, emphasis is placed on an intercellular junction (the nexus) thought to play an important role in communication. A correlation is made between the extent of thecal development and the incidence of granulosa cell nexuses in follicles of normal as well as hypophysectomized rats. If the “thec...