title: Effects of ciguatoxin and maitotoxin on the isolated guinea pig atria.
abstract: The effects of ciguatoxin (CT) and maitotoxin (MT) were studied on the isolated atria of the guinea pig. Application of CT evoked a prolonged positive inotropic effect on the electrically-driven atria and both inotropic and chronotropic effects on the spontaneously-beating right atria. The response to MT in contrast was biphasic. At low concentration (10(-8) Gm per ml) MT enhanced the atrial contractility, while at higher concentrations (5 x 10(-8) Gm per ml) it depressed the atria and frequently to a standstill. The results indicate that CT and MT have a direct action on the contractile mechanism of the heart and their effects are readily distinguishable.
mesh_terms: D000818:Animals; D002922:Ciguatoxins / Q000494:pharmacology*; D004524:Eels; D005260:Female; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D008387:Marine Toxins / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D035964:Oxocins; D000095702:Polyether Toxins
chemical_list: D002922:Ciguatoxins; D008387:Marine Toxins; D035964:Oxocins; C020394:maitotoxin; D000095702:Polyether Toxins