title: Sanguinarine: a positive inotropic alkaloid which inhibits cardiac Na+,K+-ATPase.
abstract: In isolated, isometrically contracting left guinea pig atria, sanguinarine, a benzophenanthridine alkaloid from the papaveracea Sanguinaria canadensis, produced a concentration-dependent positive inotropic effect. Between 2.3 x 10(-6) M and 6.5 x 10(-5) M, sanguinarine increased contractility by 108% which was comparable to the maximal inotropic effect of ouabain. Within the same concentration range, sanguinarine caused inhibition of Na+,K+-ATPase isolated from guinea pig myocardium. 100% inhibition of Na+,K+,ATPase activity occurred at 1 x 10(-4) M sanguinarine. The I50 for enzyme inhibition and the ED50 for the inotropic action of sanguinarine were the same (6-6.5 x 10(-6) M) indicating that both effects may be causally related.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D053119:Benzophenanthridines; D002316:Cardiotonic Agents / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007546:Isoquinolines; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000201:enzymology*; D010042:Ouabain / Q000494:pharmacology; D010617:Phenanthridines / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
chemical_list: D000470:Alkaloids; D053119:Benzophenanthridines; D002316:Cardiotonic Agents; D007546:Isoquinolines; D010617:Phenanthridines; D010042:Ouabain; C005705:sanguinarine; D000254:Sodium-Potassium-Exchanging ATPase