Lithium chloride-induced cardiovascular changes in rabbits are mediated by adenosine triphosphate- sensitive potassium channels

ABSTRACT

The effect of lithium chloride on the mean arterial blood pressure, heart rate and heart contractility was evaluated in rabbits. The intravenous administration of 50 mg/kg lithium chloride as a bolus injection into rabbits produced a progressive decrease in the mean arterial blood pressure, heart rate and heart contractility during the two hours of investigation. Pretreatment of animals with 5 mg/kg glibenclamide markedly inhibited the cardiovascular changes induced by lithium chloride. Doubling the dose of glibenclamide nearly abolished these effects of lithium chloride. Diazoxide and verapamil potentiated the relaxant effect of lithium chloride on the isolated noradrenaline-contracted aortic strips. Pretreatment with glibenclamide markedly reversed the effect of diazoxide, but not that of verapamil. The intravenous administration of lithium was capable of increasing the plasma potassium level and decreasing the intracellular levels of adenosine triphosphate in cardiac and vascular tissues in a time dependent manner