A transplantable rat Leydig cell tumor--2. Adenylyl cyclase activation by prostaglandin E1, isoproterenol and glucagon.
The responsiveness of the membrane bound adenylyl cyclase (AC) system to various hormones and hormone analogues in a transplantable rat Leydig cell tumor (H-540) has been investigated and compared with that of interstitial tissue from normal adult rats. The results can be summarized as follows: The AC of the Leydig cell tumors was stimulated by isoproterenol, epinephrine, norepinephrine, dopamine, glucagon, PGE1, PGF2 alpha and LH/hCG. The AC of the Leydig cell tumors exhibited a much greater response to PGE1 than the AC in normal interstitial tissue (5-fold and 2-fold stimulation, respectively). The AC of the Leydig cell tumours also revealed a somewhat higher response to isoproterenol than the AC of interstitial tissue (2.5-fold and 2-fold, respectively). Adenylyl cyclase in both tissues were equally stimulated by glucagon (2-fold). The LH response in the Leydig cell tumors was only half of that found in normal Leydig cells. This study indicates, that in spite of the fact that tumor Leydig cells respond to LH and produce testosterone, the response pattern of the AC is different from that of normal Leydig cells.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000527:Alprostadil; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005934:Glucagon / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology*; D007984:Leydig Cell Tumor / Q000201:enzymology*; D008297:Male; D009368:Neoplasm Transplantation; D011458:Prostaglandins E / Q000494:pharmacology*; D051381:Rats; D013736:Testicular Neoplasms / Q000201:enzymology*
D011458:Prostaglandins E; D005934:Glucagon; D000262:Adenylyl Cyclases; D000527:Alprostadil; D007545:Isoproterenol