title: Interactions of protein kinase C with receptor- and non-receptor-mediated cyclic AMP generation in swine granulosa cells.
abstract: Interactions between signal transducing systems may be important in the integrated control of cellular processes in basal and hormonally regulated cells. The swine granulosa cell provides a model to study the interactions between the cAMP and calcium-lipid-dependent signaling pathways. To this end, porcine granulosa cells were incubated in monolayer culture for 1-4 days in the presence of FSH (200 ng/ml), forskolin (85 microM), or cholera toxin (3 micrograms/ml) with or without an activator of protein kinase C, the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) (30 ng/ml). TPA had little effect on basal cAMP generation (1-4 days) or on follicle-stimulating hormone (FSH)-stimulated cAMP formation during the first 24 h. Phorbol ester did inhibit cAMP formation on day 2 (by approximately 25%), on day 3 (by approximately 70%) and on day 4 (by greater than 80%). Forskolin-mediated cAMP generation was inhibited (33-56%) on days 1-4, respectively. TPA suppressed dose-dependent FSH (3-300 ng/ml)-stimulated cAMP production on day 2, virtually abolished FSH-provoked cAMP formation on day 4 and inhibited dose-dependent forskolin-stimulated cAMP production on both days. TPA had no effect on the half-maximally effective dose, ED50, of FSH-stimulated cAMP production but did decrease the ED50 of forskolin and the maximal stimulatory effect of FSH and forskolin on days 2 and 4. Similar effects were observed with the synthetic diacylglycerols DOG (1,2-dioctanoylglycerol) and OAG (1-oleoyl-2-acetylglycerol). The TPA effect was limited to the mammalian adenylate cyclase as it had no effect on bacterially derived adenylate cyclase from Bordetella pertussis.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Internal Medicine, University of Virginia School of Medicine, Charlottesville 22908.
authors.forename: M B
authors.initials: MB
authors.lastname: Wheeler
authors.forename: J D
authors.initials: JD
authors.lastname: Veldhuis
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002772:Cholera Toxin / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000502:physiology*; D015398:Signal Transduction; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D004075:Diglycerides; D011956:Receptors, Cell Surface; D005576:Colforsin; D005640:Follicle Stimulating Hormone; D002772:Cholera Toxin; D000242:Cyclic AMP; D011493:Protein Kinase C; D019204:GTP-Binding Proteins; D013755:Tetradecanoylphorbol Acetate