Ninhibin: a sperm factor attenuates the atrial natriuretic factor mediated inhibition of adenylate cyclase: possible involvement of inhibitory guanine nucleotide regulatory protein.
The effect of ninhibin, a sperm factor extracted from bovine sperm, was studied on adenylate cyclase from rat aorta. Ninhibin treatment of the membranes activated adenylate cyclase in a concentration dependent manner. The maximal activation (approximately equal to 4-fold) was obtained at 2micrograms ninhibin and at 10 min of treatment at 37 degrees C. On the other hand, in untreated control membranes, ninhibin at 2 micrograms could stimulate adenylate cyclase by about 50-60% only. In addition, ninhibin potentiated the guanine nucleotide-, isoproterenol- and forskolin (FSK)-stimulated adenylate cyclase activities and also attenuated the GTP gamma s and atrial natriuretic factor (ANF)-mediated inhibition of enzyme activities. Furthermore the inhibition of isoproterenol- and FSK-stimulated adenylate cyclase activities by ANF was also abolished by ninhibin. These data indicate that ninhibin which has been suggested to inactivate or inhibit Ni-guanine nucleotide regulatory protein can also attenuate the ANF-receptor mediated inhibition of adenylate cyclase in rat aorta suggesting an involvement of Ni-guanine nucleotide regulatory protein in the coupling of ANF receptors to adenylate cyclase.
D000176:Acrosin; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D001011:Aorta / Q000201:enzymology; D002417:Cattle; D005576:Colforsin; D004224:Diterpenes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000494:pharmacology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D045283:Natriuretic Agents; D011506:Proteins / Q000494:pharmacology*; D051381:Rats; D013873:Thionucleotides / Q000494:pharmacology
D000067956:Adenylyl Cyclase Inhibitors; D004224:Diterpenes; D045283:Natriuretic Agents; D011506:Proteins; D013873:Thionucleotides; D005576:Colforsin; D006165:Guanylyl Imidodiphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D010450:Endopeptidases; C045523:ninhibin; D000176:Acrosin; D019204:GTP-Binding Proteins; D007545:Isoproterenol