title: Inhibition of adenylate cyclase of catfish and rat hepatocyte membranes by 9-(tetrahydro-2-furyl)adenine (SQ 22536).
abstract: The adenosine analogue 9-(Tetrahydro-2-furyl)adenine, SQ 22536, inhibited adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity of crude membrane preparations from catfish (Ictalurus melas) and rat isolated hepatocytes in a non-competitive manner. The IC50s were reduced in the presence of NaF. SQ 22536 reduced the activity of adenylate cyclase also in the presence of increasing concentrations of GTP, as well as Mg++ and Mn++. In the presence of catecholamines (epinephrine, norepinephrine, isoproterenol, phenylephrine) SQ 22536 reduced their activating effect on adenylate cyclase in both catfish and rat membranes. SQ 22536 also inhibited the effect of glucagon (0.1 microM) on rat membrane cyclase activity.
authors.affiliation: Institute of General Physiology, University of Ferrara, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Fabbri
authors.forename: L
authors.initials: L
authors.lastname: Brighenti
authors.forename: C
authors.initials: C
authors.lastname: Ottolenghi
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D005934:Glucagon / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007059:Ictaluridae; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology; D013045:Species Specificity
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; C017759:9-(tetrahydro-2-furyl)-adenine; D010656:Phenylephrine; D006160:Guanosine Triphosphate; D012969:Sodium Fluoride; D005934:Glucagon; D000225:Adenine; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine