Co-Authors:
Litichever, N., Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
Gershon, E., Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
Dekel, N., Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Koch, Y., Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
Abstract:
We have recently demonstrated that the rat ovary expresses LHβ, FSHβ, and the common alpha subunit mRNA. In the present report, we studied the regulation of LHβ and of gonadotropin-releasing hormone (GnRH) mRNA expression in granulosa cells that were isolated from immature rats treated with either estrogen or pregnant mare serum gonadotropin (PMSG). In both cell types, GnRH agonist treatment resulted in a decrease in LHβ mRNA expression. However, only in cells derived from PMSG-treated rats, GnRH treatment produced an increase in GnRH mRNA expression. A markedly increased GnRH mRNA expression was also obtained in granulosa cells derived from PMSG-primed rats in response to LH. In addition, FSH reduced the expression of LHβ mRNA in granulosa cells from estrogen-primed rats. These results suggest that the expression of LHβ in the ovary is regulated by locally produced GnRH and by FSH from either the ovary or the pituitary. © Humana Press 2009.