title: Na+ amplifies adenosine receptor-mediated inhibition of adipocyte adenylate cyclase.
abstract: Membrane preparations of hamster adipocytes were used to study the inhibition of adenylate cyclase by the adenosine analogue, N6-phenylisopropyladenosine (PIA). Inhibition by PIA was half-maximal and maximal (about 40%) at about 0.03 and 1 micro M, respectively, and was antagonized by 3-isobutyl-1-methylxanthine in a competitive manner. Like other hormone receptor-mediated inhibitions of the adipocyte adenylate cyclase, the adenosine receptor-mediated action on the enzyme was absolutely dependent on GTP and was amplified by sodium ions.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D006160:Guanosine Triphosphate / Q000378:metabolism; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011983:Receptors, Purinergic; D012964:Sodium / Q000494:pharmacology*
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D011956:Receptors, Cell Surface; D011983:Receptors, Purinergic; D010660:Phenylisopropyladenosine; D006160:Guanosine Triphosphate; D012964:Sodium; D000262:Adenylyl Cyclases; D015056:1-Methyl-3-isobutylxanthine