Inhibitory effect of enkephalin on insulin secretion in healthy subjects and in non insulin-dependent diabetic subjects.

The administration of the long-acting met-enkephalin analogue (FK 33-824, Sandoz; Basel Switzerland) inhibits insulin secretion induced by glucose (oral and intravenous) and nonglucose (arginine and breakfast) secretagogues in both normal subjects and in patients with noninsulin-dependent diabetes mellitus. The plasma glucose rise triggered by oral glucose and breakfast is reduced by FK in both groups of subjects, suggesting for the opioid peptide an effect in delaying glucose absorption. The data suggest a negative role for enkephalin in the regulation of insulin secretion in both normal and noninsulin-dependent diabetic subjects.