IMMUNOLOGIC STUDIES IN INSULIN RESISTANCE. III. MEASUREMENT OF AN INSULIN ANTAGONIST IN THE SERUM OF AN INSULIN-RESISTANT PATIENT BY THE BLOOD SUGAR CURVE METHOD IN MICE

Abstract

A technic is described by which interference with the hypoglycemic action of insulin was readily demonstrated with small quantities of serum from a patient with insulin resistance. Tests done with normal serum, serum from a patient with uncomplicated diabetes and serum obtained from the insulin resistant patient at a time when resistance was apparently absent, failed to interfere with the action of insulin. In performing the test, fasting blood samples were obtained from the tails of a group of 6 adult white mice following which 0.2 ml. of a mixture of serum and insulin was injected intraabdominally. Two subsequent blood samples were obtained after 30 and 60 mins. Sugar detns. were made by the Folin micro-method. With this method, the insulin-neutralizing activity of the patient''s serum could be measured in a roughly quantitative manner. Calculation showed that the patient''s plasma contained sufficient neutralizing activity to account for the patient''s resistance to insulin. Evidence has been presented previously indicating that there was an immunologic basis for the patient''s resistance. It is pointed out that the mechanism operating in this patient to produce insulin resistance could readily account for the extreme degrees of resistance occasionally encountered.