Effects of two monocarboxylic ionophores, grisorixin and alborixin, on cardiovascular function and plasma cation concentrations in the anesthetized dog.
Grisorixin and alborixin are two monocarboxylic ionophores of the nigericin group which carry potassium preferentially over sodium. We studied their cardiovascular effects in anesthetized dogs. Grisorixin (2 mg/kg) and alborixin (1 mg/kg) produced a dramatic increase in ventricular contractile force (+250 and +320%, respectively) and in systolic and diastolic arterial pressures. At the same time, they induced a marked increase in plasma potassium in the coronary sinus and hepatic vein and a lesser increase in the renal and deep femoral veins. The concomitant modifications of the electrocardiogram were similar to those usually described in hyperkalemia, reflecting the effect of grisorixin and alborixin on plasma potassium. The parallel decrease in plasma sodium in the coronary sinus was more marked with alborixin than with grisorixin. These results suggest that the ionophores alter the intracellular ionic state of the myocardium, which may partly explain their positive inotropic effect and the greater effect of alborixin.
D000758:Anesthesia; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002412:Cations / Q000097:blood*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007476:Ionophores / Q000494:pharmacology*; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009550:Nigericin / Q000031:analogs & derivatives / Q000494:pharmacology*; D011714:Pyrans / Q000494:pharmacology; D013997:Time Factors
D000900:Anti-Bacterial Agents; D001786:Blood Glucose; D002412:Cations; D007476:Ionophores; D011714:Pyrans; C012708:alborixin; C010731:grisorixin; D009550:Nigericin