title: Effect of extracellular adenosine 5'-triphosphate on Ca2+ efflux from freshly isolated adult rat cardiomyocytes.
abstract: The effect of extracellular adenosine 5'-triphosphate (ATP) on Ca2+ efflux from freshly isolated adult rat cardiomyocytes was examined. ATP stimulated the efflux of 45Ca2+ from the cells in a concentration-dependent manner (0.01-1 mM). The 45Ca2+ efflux from the cells was also stimulated by adenosine-5'-O-(3-thiotriphosphate)(ATP-gammas) and alpha,beta-methylene-ATP and adenosine 5'-diphosphate, but not by adenosine 5'-monophosphate and adenosine. The ATP-stimulated 45Ca2+ efflux was not affected by deprivation of the extracellular Ca2+, but was dependent on the presence of extracellular Na+. These results indicate that ATP stimulates extracellular Na+-dependent 45Ca2+ efflux from freshly isolated adult rat cardiomyocytes, probably through its stimulatory effect on the plasma membrane P2 purinoceptors which may couple to Na+/Ca2+ exchange.
authors.affiliation: Department of Cardiovascular Surgery and Pharmacology, School of Medicine, University of Tokushima, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hori
authors.forename: M
authors.initials: M
authors.lastname: offhizumi
authors.forename: T
authors.initials: T
authors.lastname: Kitagawa
authors.forename: F
authors.initials: F
authors.lastname: Chikugo
authors.forename: T
authors.initials: T
authors.lastname: Kawahito
authors.forename: I
authors.initials: I
authors.lastname: Katoh
authors.forename: H
authors.initials: H
authors.lastname: Houchi
authors.forename: M
authors.initials: M
authors.lastname: Oka
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000241:Adenosine; D002118:Calcium