Effect of phorbol ester and phospholipase C on LH-stimulated steroidogenesis in purified rat Leydig cells.
When the phorbol ester, 4 beta-phorbol-12-myristate-13-acetate (PMA) or bacterial phospholipase C (PL-C) is added to a preparation of purified adult rat Leydig cells, containing 2 mM CaCl2, a time- and dose-dependent decreases of LH-stimulated testosterone production is observed. After a 3 h stimulation with oLH (100 ng/ml), PMA (100 ng/ml) and PL-C (1.6 U/ml) do not affect the cell viability or the hCG specific binding, while cAMP accumulation is significantly reduced; cAMP-stimulated steroidogenesis is diminished only in the presence of PL-C. These observations suggest that in vitro: (i) activated Ca2+- and phospholipid-dependent protein kinase is implicated in the regulation of rat Leydig cell steroidogenesis by LH at a step before the adenylate cyclase; (ii) phospholipids play an important role in cAMP-stimulated testosterone synthesis.
Papadopoulos
V
V
Carreau
S
S
Drosdowsky
M A
MA
D000818:Animals; D006063:Chorionic Gonadotropin / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D066298:In Vitro Techniques; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism; D010740:Phospholipases / Q000494:pharmacology*; D011493:Protein Kinase C; D011494:Protein Kinases / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000096:biosynthesis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D010738:Type C Phospholipases / Q000494:pharmacology*
D006063:Chorionic Gonadotropin; D010703:Phorbol Esters; D010704:Phorbols; D010716:Phosphatidylinositols; D013739:Testosterone; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C; D010740:Phospholipases; D010738:Type C Phospholipases; D013755:Tetradecanoylphorbol Acetate