title: Negative inotropic effect of carbachol and interaction between acetylcholine receptor-operated potassium channel (K.ACh channel) and GTP binding protein in mouse isolated atrium--a novel methodological trial.
abstract: Interaction between acetylcholine receptor-operated potassium channel (K.ACh channel) and GTP binding protein was examined by an immunoprecipitation-Western blotting system in mouse isolated atrium. The carbachol-induced negative inotropic action in indomethacin-pretreated mouse atrium was significantly inhibited by a K.ACh channel blocker, tertiapin or atropine. Kir3.1 K.ACh channel (Kir3.1) was immunoprecipitated with a mouse anti-Kir3.1 antibody. Coprecipitating Gβ with Kir3.1, detected by Western blotting, was significantly augmented by carbachol. Atropine, but not tertiapin, significantly inhibited the carbachol-induced coprecipitating Gβ with Kir3.1. The data indicate that immunoprecipitation with Kir3.1 and Western blotting of Gβ system is a useful method for assessing interaction between K.ACh channel and GTP binding protein in mouse atrium.
authors.affiliation: Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Higashi 23 bancho 35-1, Towada city, Aomori 034-8628, Japan.
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Okada
authors.forename: Chihiro
authors.initials: C
authors.lastname: Noma
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamawaki
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hara
mesh_terms: D000818:Animals; D000906:Antibodies; D001285:Atropine / Q000494:pharmacology; D001514:Bee Venoms / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology*; D018680:Cholinergic Antagonists / Q000494:pharmacology; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits / Q000235:genetics / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006325:Heart Atria / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D009200:Myocardial Contraction / Q000187:drug effects*; D026902:Potassium Channel Blockers / Q000494:pharmacology
chemical_list: D000906:Antibodies; D001514:Bee Venoms; D018680:Cholinergic Antagonists; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; D044387:GTP-Binding Protein beta Subunits; D026902:Potassium Channel Blockers; C029738:tertiapin; D001285:Atropine; D002217:Carbachol; D019204:GTP-Binding Proteins