Effect of propranolol on some adrenaline- and insulin-induced metabolic changes in man.

The effect of propranolol on adrenaline- and insulin-induced changes in blood glucose pyruvate, lactate, phosphorus and potassium were examined in 29 apparently healthy volunteers. A slight, but significant reduction in adrenaline-induced hyperglycaemia was noted, along with suppression of both the increase in pyruvate and lactate and the decrease in phosphorus and potassium attributable to this catecholamine. There was no significant change in the blood glucose curve after insulin whereas insulin-induced increases in pyruvate and lactate were reduced by 44% +/- 17.7 (mean +/- SEM) and 78% +/- 5.4 respectively, and the fall in phosphorus by 48% +/- 3.1; the decrease in potassium, however, was not significantly modified. These findings suggest that changes in plasma pyruvate, lactate and inorganic phosphates induced by insulin, and regarded as espressions of its peripheral metabolism, are greatly dependent on the beta-adrenergic effect of the endogenous catecholamines released during the time when blood glucose values are low.