title: Evidence for A2 adenosine receptor-mediated effects on adenylate cyclase activity in rat ovarian membranes.
abstract: Effects of adenosine analogues on adenylate cyclase activity in preovulatory rat ovarian membranes were studied. Adenosine analogues stimulated adenylate cyclase activity in the following rank order of potency: NECA (5'-(N-ethyl)carboxamidoadenosine) greater than 2-chloroadenosine greater than N6-(R-phenylisopropyl)-adenosine greater than N6-(S-phenylisopropyl)adenosine. The apparent EC50 for NECA was 0.28 microM. The adenosine receptor antagonist 8-phenyltheophylline (10 microM) displaced the dose-response curve for NECA to the right, increasing the EC50 for NECA about one order of magnitude. NECA also additively increased maximally FSH-stimulated adenylate cyclase activity. These results suggest that adenosine stimulates adenylate cyclase in rat ovarian membranes via adenosine receptors of the A2 type.
authors.affiliation: Department of Physiology, University of Göteborg, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Billig
authors.forename: S
authors.initials: S
authors.lastname: Rosberg
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide); D000262:Adenylyl Cyclases / Q000096:biosynthesis / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D010053:Ovary / Q000201:enzymology*; D051381:Rats; D011983:Receptors, Purinergic / Q000378:metabolism*; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D011983:Receptors, Purinergic; D019830:Adenosine-5'-(N-ethylcarboxamide); D005640:Follicle Stimulating Hormone; D013806:Theophylline; D000242:Cyclic AMP; C028322:8-phenyltheophylline; D000262:Adenylyl Cyclases; D000241:Adenosine