Repaglinide, glibenclamide and glimepiride administration to normal and hereditarily diabetic rats.

Repaglinide (1 microg/g body wt), glibenclamide (10 microg/g) or glimepiride (10 microg/g) were administered orally to either fed or overnight fasted normal rats and hereditarily diabetic animals (GK rats). In both fed and starved normal rats, repaglinide provoked a greater and more rapid increase in plasma insulin concentration and an earlier fall in glycemia than those observed after administration of the hypoglycemic sulfonylureas. Likewise, in fed GK rats, the plasma insulin concentration was already increased by 30.0 +/- 1.6% 15 min after administration of repaglinide, whilst a sizeable insulinotropic action of the sulfonylureas was only recorded at much later times. Except for a lower glycemia at the 240th min of the test, there was little to distinguish, in starved GK rats, between control experiments including the oral administration of the solution of carboxymethylcellulose used as vehicle and the experiments conducted with the antidiabetic agents. Several converging observations indicated that glimepiride stimulated insulin release more promptly than glibenclamide. It is proposed that advantage can be taken from these vastly different time-courses of the hormonal and metabolic response to distinct hypoglycemic agents to optimize the control of glucose homeostasis in non-insulin-dependent diabetic subjects.