Potentiation by methyl pyruvate of GLP-1 insulinotropic action in normal rats

Methyl pyruvate (MP) stimulates insulin release both in vivo and in vitro. The present study aims at investigating whether MP is also able to enhance the B-cell secretory response to glucagon-like peptide 1 (GLP-1). In anaest hetized rats receiving a primed constant infusion of MP, the ester augmente d plasma insulin concentration before GLP-1 injection and potentiated the i nsulinotropic action of the intestinal hormone. MP infusion also augmented plasma D-glucose concentration, whether in the absence or presence of GLP-1 . A further rise in plasma D-glucose concentration was observed when the in fusion of MP was halted, this coinciding with a fall in plasma insulin conc entration. Whilst documenting that MP indeed enhances the B-cell secretory response to GLP-1, these findings do not suggest that MP is an appropriate tool for optimizing the hypoglycaemic action of the enteric hormone in the treatment of type-2 diabetes mellitus.