title: Positive chronotropic and negative inotropic effects induced by potassium chloride in the isolated canine atrium.
abstract: The effects of potassium chloride on inotropic and chronotropic activity were investigated in five isolated canine atrium preparations which were suspended in a bath and perfused with arterial blood from the carotid artery of the heparinized support dog. Potassium chloride administered into the cannulated sinus node artery in a dose range of 100 mug-1 mg produced a dose-related negative inotropic and a positive chronotropic effect. These effects were not influenced by treatment with either atropine or propranolol. From these results, it is concluded that potassium had a direct negative effect on atrial contractility and a direct positive effect on atrial rate.
mesh_terms: D000818:Animals; D003864:Depression, Chemical; D004285:Dogs; D006325:Heart Atria / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects*; D011189:Potassium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D013268:Stimulation, Chemical
chemical_list: D011189:Potassium Chloride