Intracellular pH and electrolytes in human skeletal muscle during adrenaline and insulin infusions.

Abstract

There is evidence that both beta-adrenergic stimulation and insulin are of importance in controlling intracellular pH. Therefore we have investigated the influence of intravenous infusion of adrenaline or insulin glucose (euglycaemic clamp) on pH and electrolyte composition in resting skeletal muscle (m. quadriceps femoris) and arterial blood in six healthy subjects. A decrease in the arterial potassium concentration was observed during infusion of adrenaline and is in conformity with previous studies. Both adrenaline and insulin infusions resulted in an increased lactate content of muscle and blood, indicating an enhanced glycolysis. The intracellular concentrations of K+, Na+, Mg2+ and H+, however, remained unchanged during the adrenaline infusions as well as during infusions of insulin. It is concluded that increasing the plasma adrenaline and insulin concentrations to levels well above the physiological range (adrenaline) or in the upper physiological range (insulin) does not affect the concentrations of electrolytes and hydrogen ions in resting human muscle to any appreciable extent.