Insulin and an inhibitor of glucose uptake, in protein fractions of normal human plasma

Abstract

Protein fractions were prepared from normal human plasma by fractional precipitation with ethanol and an improved method of zone electrophoresis on columns of treated cellulose, and their effect on the uptake of glucose by isolated rat diaphragm was investigated. Insulin was detected in a protein fraction containing slower-moving albumin and a1-globulins and in one containing [alpha]2 and [beta]-globulins. No insulin could be detected in gamma-globulins. An inhibitor of glucose uptake by isolated diaphragm was identified in a fraction containing [alpha]2 - and [beta]-globulins.