New alpha 2-adrenergic blocker (DG-5128) improves insulin secretion and in vivo glucose disposal in NIDDM patients.

Effects of oral administration of DG-5128, a new oral hypoglycemic agent, on glycemic control after a mixed meal and an in vivo glucose disposal were measured in subjects with nonobese non-insulin-dependent diabetes mellitus (NIDDM). Oral administration of DG-5128 significantly (P less than .05) enhanced insulin secretion both 30 and 60 min after a mixed meal (550 kcal), with a concomitant decrease in postprandial plasma glucose levels at 60 and 120 min. Glucose disposal rate between the 2nd and 4th h of a euglycemic insulin clamp, developed through a constant infusion of insulin (0.77 mU X kg-1 X min-1) together with somatostatin (80 ng X kg-1 X min-1), was 2.5-fold higher in a DG-5128-treated group (P less than .01) than in a control group. However, there was no difference between the two groups in either plasma glucose concentration or plasma insulin concentration at either the 2nd or the 4th h. These results indicate that DG-5128 is effective in controlling plasma glucose levels in subjects with NIDDM by stimulation of both insulin secretion and in vivo glucose disposal.