“Plasma Insulin Activity' in Human Diabetes During Hypoglycemic Response to Tolbutamide and Indole-3-Acetic Acid

Summary

Hypoglycemic responses of normal and diabetic men to tolbutamide and indole-3-acetic acid were similar both qualitatively and quantitatively. These substances, respectively, depressed fasting glucose levels 22% and 11% in normal subjects: 44% and 35% in elderly patients with mild diabetes; and 1% and 7% in uncontrolled juvenile diabetics. Normal individuals and mild diabetics demonstrated significant “insulin activity' in their fasting plasmas, and both groups exhibited sharp increases in insulin activity after ingestion of glucose. Insulin activity was not detectable in blood of juvenile diabetics either before or after glucose. In no individual, however, whether normal or diabetic, was the hypoglycemic response to tolbutamide or indole-3-acetic acid accompanied by increased “plasma insulin activity' in peripheral blood.