Progesterone stimulation by LH involves the phospholipase-C pathway in bovine luteal cells.
Luteinizing hormone (LH)-stimulated steroidogenesis in luteal cells is known to be mediated through the activation of cyclic AMP (cAMP)-dependent protein kinase, and to be also modulated by calcium-dependent mechanisms. In the present study, we tested the hypothesis that LH stimulates progesterone (P4) production in bovine luteal cells through activation of phospholipase (PL) C by using a cell culture system. Bovine mid-luteal cells (Days 8-12 of the estrous cycle) were cultured for 24 h and then exposed to a PLC inhibitor (U-73122; 10 microM) with or without LH (10 ng/ml) for 4 h. U-73122 blocked LH-stimulated P4 production without affecting cAMP accumulation. Moreover, exposure of luteal cells to PLC increased P4 production in a dose-dependent manner. These results support the hypothesis that the luteotropic action of LH in bovine luteal cells is mediated not only by activation of adenylate cyclase but also by activation of PLC.
Nishimura
Ryo
R
Laboratory of Reproductive Endocrinology, Graduate School of Natural Science and Technology, Okayama University, Japan.
Shibaya
Masami
M
Skarzynski
Dariusz J
DJ
Okuda
Kiyoshi
K
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002455:Cell Division; D006063:Chorionic Gonadotropin / Q000378:metabolism; D003338:Corpus Luteum / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism; D008184:Luteal Cells / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D013997:Time Factors; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D004791:Enzyme Inhibitors; D004963:Estrenes; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D011374:Progesterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D010738:Type C Phospholipases; D000262:Adenylyl Cyclases