EFFECT OF INSULIN ON CARBOHYDRATE METABOLISM AND ON POTASSIUM IN THE FOREARM OF MAN*

Abstract

Insulin, injected continuously at constant rate into the brachial artery at a final concentration of 200 to 700 [mu]U per ml of brachial arterial plasma, increased forearm glucose uptake promptly and ultimately by about tenfold. There was no evidence that any but a minor fraction of this additional glucose uptake was dissimilated to lactate and CO2 during the 1.5 to 2 hours after onset of insulin infusion. Under the same conditions, insulin provoked K uptake by forearm tissues as promptly as it promoted glucose entry but, on the basis of the relative magnitudes of K and of glucose uptake and of the differences in their time course, classic hypotheses relating these 2 effects of insulin appear untenable.