Potentiation and prolongation of the insulinotropic action of glucagon-like peptide 1 by methyl pyruvate or dimethyl ester of l-glutamic acid in a type 2 diabetes animal model

Methyl pyruvate and the dimethyl ester of l-glutamic acid were administered intravenously, as a primed constant infusion (1.0–2.0 µmol followed by 0.5–1.0 µmol/min, both expressed per gram of body wt), in adult rats that had been injected with streptozotocin during the neonatal period. Each ester augmented plasma insulin concentration and potentiated and/or prolonged the insulinotropic action of glucagon-like peptide 1 (GLP-1) injected intravenously (5 pmol/g of body wt) at min 5 of the test. It is proposed, therefore, that suitable nonglucidic nutrients, susceptible to bypassing the site-specific defects of d-glucose transport and metabolism responsible for the preferential impairment of the B-cell secretory response to d-glucose in non-insulin-dependent diabetes, could be used to optimize the insulinotropic action of GLP-1.