Comparative effects of ouabain on isolated papillary muscle from tree shrews, guinea-pigs and rats.
Inotropic effects of ouabain were investigated in the isolated papillary muscle preparations of the tree shrew (Tupaia glis), guinea-pigs and rats. In the guinea-pig and shrew papillary muscles, ouabain at concentrations of 10(-8) to 3 x 10(-7) M caused a concentration-dependent positive inotropic response in a similar magnitude, while in the rat, ouabain at concentrations of 10(-7) to 3 x 10(-6) M elicited negative inotropic one. Either phentolamine or pindolol in a concentration sufficient to block the alpha- and beta-adrenoceptors did not antagonize the positive inotropic effect of ouabain in the papillary muscle preparation of the shrews.
Koga
T
T
Department of Pharmacology, Fujigotemba Research Laboratories, Chugai Pharmaceutical Co. Ltd., Shizuoka, Japan.
Shiraki
Y
Y
Sakai
K
K
D000818:Animals; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D010042:Ouabain / Q000494:pharmacology*; D010210:Papillary Muscles / Q000187:drug effects; D010646:Phentolamine / Q000494:pharmacology; D010869:Pindolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012788:Shrews
D010042:Ouabain; D010869:Pindolol; D010646:Phentolamine