THE PHYSIOLOGIC ACTION OF INSULIN ON GLUCOSE-UPTAKE AND ITS RELEVANCE TO THE INTERPRETATION OF THE METABOLIC-CLEARANCE RATE OF GLUCOSE

Abstract

Glucose uptake (Ru) is dependent upon the concentrations of both glucose and insulin. The metabolic clearance rate of glucose (MCRG), has been used as an in vivo measure of insulin action, because it was said to be independent of the prevailing glucose concentration. The validity of this assumption has recently been challenged. In this study, the effect of insulin concentration on the rate of glucose uptake (Ru) and on the MCRG was studied during euglycemia (5.1 +/- 0.3 mmol/L) and moderate hyperglycemia (10.4 +/- 0.5 mmol/L) in 17 experiments on nine normal ambulant volunteers. Stable plasma insulin levels were maintained with fixed infusion rates of insulin (0-300 mU/kg/h) and somatostatin..