The relationship between endogenous serum insulin concentration and glucose uptake in the forearm muscles of nondiabetics.

IN A SERIES OF EXPERIMENTS ON THE HUMAN FOREARM, PREPARATION DESIGNED TO EXAMINE THE EFFECTS OF VARIATIONS IN IMMUNOLOGICALLY DETERMINED ENDOGENOUS SERUM INSULIN LEVELS AND OF BLOOD GLUCOSE CONCENTRATIONS ON MUSCULAR GLUCOSE UPTAKE, THE FOLLOWING RESULTS WERE OBTAINED: (a) A highly significant correlation between muscular glucose uptake and simultaneous arterial serum insulin concentration. (b) No correlation between glucose uptake and simultaneous arterial blood glucose concentration during hyperglycemia. (c) A maximal insulin effect on muscular glucose uptake at arterial serum insulin concentrations at about 200 muU/ml. This observation is, however, based on only a few experiments.