title: Roles of Ca2+ on the inositol 1,4,5-trisphosphate-induced release of Ca2+ from saponin-permeabilized single cells of the porcine coronary artery.
abstract: The release of Ca2+ from the intracellular store site, as induced by inositol 1,4,5-trisphosphate, was studied in relation to free Ca2+ concentrations or amounts of stored Ca2+ in smooth muscle cells. The maximal Ca2+ release induced by inositol 1,4,5-trisphosphate was observed when the amount of Ca2+ in the store site was about 50% of the maximal capacity of the Ca2+ storage, and when the extravesicular free Ca2+ concentration was less than 1.5 X 10(-6) M. The Ca2+ release induced by inositol 1,4,5-trisphosphate was accelerated by ATP and 5'-adenylylimidodiphosphate (AMPPNP), but not by ADP and AMP. This inositol 1,4,5-trisphosphate-induced Ca2+ release appeared to be specific for intracellular Ca2+ store sites (mainly sarcoplasmic reticulum), and this Ca2+ release was not apparent in the sarcolemmal fraction.
authors.forename: E
authors.initials: E
authors.lastname: Suematsu
authors.forename: M
authors.initials: M
authors.lastname: Hirata
authors.forename: T
authors.initials: T
authors.lastname: Sasaguri
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: H
authors.initials: H
authors.lastname: Kuriyama
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D007700:Kinetics; D012503:Saponins / Q000494:pharmacology*; D013403:Sugar Phosphates / Q000494:pharmacology*; D013552:Swine
chemical_list: D007295:Inositol Phosphates; D012503:Saponins; D013403:Sugar Phosphates; D000266:Adenylyl Imidodiphosphate; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate; D002118:Calcium