The effects of glibenclamide treatment on insulin secretion and on insulin binding to erythrocytes in type II diabetes mellitus.

1. Eleven patients with type II diabetes mellitus were studied prior to, and after short- (10 days) and long-term (6 months) glibenclamide treatment. 2. A marked decrease in glucose level was observed after short- and long-term therapy using the oral glucose tolerance test (OGTT) and diet test (DT). 3. After short-term therapy, insulin level increased by 52.5% with the OGTT and by 37.6% with the DT; after long-term therapy, the increases were 78.6% and 69.5%, respectively. 4. Insulin binding to erythrocytes was unchanged by short- or long-term glibenclamide therapy. 5. These data suggest that the hypoglycemic effect of glibenclamide results from an increase in insulin secretion and that extrapancreatic actions at the receptor or post-receptor level are not necessarily involved.