title: The role of GTP in prostaglandin E1 stimulation of adenylate cyclase in platelet membranes.
abstract: Adenylate cyclase activity in platelet membrane preparations was measured in the presence of prostaglandin E1 (PGE1), GTP and a non-hydrolysable analogue of GDP, guanosine 5'-[beta-thio]diphosphate (GDP[beta S]). A dose-dependent inhibition of adenylate cyclase by GDP[beta S] was observed that could be reversed either by adding increased amounts of GTP or of PGE1.
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000097:blood*; D000527:Alprostadil; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D011458:Prostaglandins E / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D011458:Prostaglandins E; D013873:Thionucleotides; D006153:Guanosine Diphosphate; C023427:guanosine 5'-O-(2-thiodiphosphate); D006160:Guanosine Triphosphate; D000262:Adenylyl Cyclases; D000527:Alprostadil