Adrenergic beta blockade and changes in plasma potassium following epinephrine administration

Injection of epinephrine, 5 μg/kg in the dog produced, among other effects, two well known effects on metabolism: hyperglycemia and a transient hyperkalemia followed by hypokalemia. The effects were compared with those found in dogs pretreated with a beta adrenoceptor blocking agent. Our results show that after either 0.05 mg/kg or 0.5 mg/kg of d, 1-propranolol, hyperglycemia and hypokalemia to epinephrine were significantly changed. The early increase of serum potassium by epinephrine was reduced and delayed by the beta blocking agent; the hypokalemic effect was clearly prevented by the three doses of propranolol used (0.05, 0.5 and 2 mg/kg) suggesting a possible relation between the mechanism producing hypokalemia and the beta adrenoceptors blocked by propranolol.