title: P2 receptor-mediated inhibition of adenylyl cyclase in PC12 cells.
abstract: PC12 pheochromocytoma cells have P2 receptors which are coupled to Ca2+ influx and catecholamine release. Previously we reported that ATP stimulated cyclic AMP accumulation at low concentrations up to 100 microM but showed inhibitory effects above this concentration [Yakushi, Y., Watanabe. A.. Murayama, T., Nomura, Y., 1996. Eur. J. Pharmacol. (314) 243-248]. In this study we investigated the characteristics of the inhibitory effects of ATP analogs. In the presence of 10 microM forskolin, an activator of adenylyl cyclase, ATP, adenosine 5'-O-(3-thiotriphosphate) (ATPgammaS), 2',3'-O-(4-benzoyl) benzoyl ATP, 2-methylthio ATP and adenosine 5'-O-(2-thiodiphosphate) inhibited cyclic AMP accumulation in a dose-dependent manner from 100 microM. UTP, alphabeta and betagamma-methylene ATP had no or very limited effects. The relative order of ATP analogs suggests that the ATP receptor appears to be P2Y-like. However, suramin, an antagonist of P2X and P2Y receptors, and reactive blue-2, which inhibited betagamma-methylene ATP-induced cyclic AMP accumulation, did not modify the inhibitory effect of ATPgammaS. Treatment with pertussis toxin, which completely abolished the effect of carbachol, had no effect on the action of ATP over 300 microM. The existence of a new type of ATP receptor-mediated inhibition of adenylyl cyclase is proposed in PC12 cells.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Murayama
authors.forename: Y
authors.initials: Y
authors.lastname: Yakushi
authors.forename: A
authors.initials: A
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Nomura
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D016716:PC12 Cells; D037342:Pertussis Toxin; D011493:Protein Kinase C / Q000378:metabolism; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D013498:Suramin / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D037361:Adenylate Cyclase Toxin; D000067956:Adenylyl Cyclase Inhibitors; D000970:Antineoplastic Agents; D058919:Purinergic P2 Receptor Antagonists; D010566:Virulence Factors, Bordetella; D005576:Colforsin; D013498:Suramin; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D037342:Pertussis Toxin; D011493:Protein Kinase C; D002118:Calcium