The positive inotropic effect of the aqueous extract of Convallaria keiskei in beating rabbit atria.
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.
Choi
Deok Ho
DH
Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Jeonbuk, 570-749, Republic of Korea.
Kang
Dae Gill
DG
Cui
Xun
X
Cho
Kyung Woo
KW
Sohn
Eun Jin
EJ
Kim
Jin Sook
JS
Lee
Ho Sub
HS
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
D002316:Cardiotonic Agents; D002317:Cardiovascular Agents; D010936:Plant Extracts; D000242:Cyclic AMP; D004110:Diltiazem; D011188:Potassium