title: The positive inotropic effect of the aqueous extract of Convallaria keiskei in beating rabbit atria.
abstract: The positive inotropic effect of the aqueous extract of Convallaria keiskei (ACK) and the possible mechanisms responsible for this effect were investigated in beating rabbit atria. ACK significantly increased atrial stroke volume, pulse pressure, and cAMP efflux in beating rabbit atria. The effects were not altered by pre-treatment with staurosporine and diltiazem, a non-selective protein kinase inhibitor and an L-type Ca2+ channel blocker, respectively. In addition, ACK markedly increased the K+ concentration in the beating atria-derived perfusate. Convallatoxin, a well-known digitalis-like cardiac glycosidic constituent of ACK, also increased atrial stroke volume and pulse pressure but did not alter the cAMP efflux level. The increases in atrial stroke volume and pulse pressure induced by convallatoxin were not also altered by pre-treatment with diltiazem. These results suggest that the ACK-induced positive inotropic effect in beating rabbit atria may, at least in part, be due to the digitalis-like activity of convallatoxin.
authors.affiliation: Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk, 570-749, Republic of Korea.
authors.forename: Deok Ho
authors.initials: DH
authors.lastname: Choi
authors.forename: Dae Gill
authors.initials: DG
authors.lastname: Kang
authors.forename: Xun
authors.initials: X
authors.lastname: Cui
authors.forename: Kyung Woo
authors.initials: KW
authors.lastname: Cho
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Sohn
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Kim
authors.forename: Ho Sub
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002317:Cardiovascular Agents / Q000494:pharmacology; D031405:Convallaria / Q000737:chemistry*; D000242:Cyclic AMP / Q000378:metabolism; D004110:Diltiazem / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology; D011188:Potassium / Q000737:chemistry / Q000378:metabolism; D011817:Rabbits; D011863:Radioimmunoassay; D013318:Stroke Volume / Q000187:drug effects
chemical_list: D002316:Cardiotonic Agents; D002317:Cardiovascular Agents; D010936:Plant Extracts; D000242:Cyclic AMP; D004110:Diltiazem; D011188:Potassium