Epinephrine Protection Against Fatal Hyperkalemia in Adrenalectomized Rats

Abstract

A hyperkalemia and cardiac standstill resulting in 100% mortality were induced within 20 min. after the admn. of 2 ml. of a 50% glucose soln. into the stomachs of adrenalectomized rats. Pre-treatment with 0.04 mg. epinephrine/100 g. of body wt., injd. subcut. 60 min. before admn. of the glucose soln. protected the adrenalectomized rats. Pre-treatment with 2 ml. of lipoadrenal extract 120 min. before giving the glucose soln. did not protect the adrenalectomized rats. The admn. of the glucose soln. to demedullated rats with functional adrenal cortices resulted in a 50% mortality. The difference in mortality of the adrenalectomized and demedullated rats was ascribed to the initial relatively "low" plasma K concn. of the latter group. Epinephrine pretreatment protected the demedullated group, too. Control groups of rats given 2 ml. of mineral oil or physiological saline per os were not fatally affected by the procedure nor was the plasma K level influenced. These data are discussed as indicating that epinephrine protected the exptl. groups of rats by inducing a lower than "normal" plasma K concn. and "blocking" a change to supra-normal levels after the glucose per os.