Metabolism of glycerol-1,2,3-trimethylsuccinate in rat pancreatic islets.

The metabolism of 14C-labelled glycerol-1,2,3-trimethylsuccinate (2.0 mM) was examined in rat pancreatic islets. The oxidation of the glycerol moiety of the ester was negligible relative to that of its succinate residues. The oxidation of glycerol-1,2,3-trimethyl[1,4-(14)C]succinate was two times higher than that of glycerol-1,2,3-trimethyl[2,3-(14)C]succinate, this difference being matched by a higher generation of 14C-labelled acidic metabolites and amino acids from the latter than from the former tracer. The total generation of 14CO2 from the ester, uniformly labelled except in its methyl groups, was close to that found for the oxidation of 1.0 mM D-[U-(14)C]glucose. These findings thus reveal that glycerol-1,2,3-trimethylsuccinate is efficiently metabolized in islet cells and support the idea that this ester could be used as a nutrient to bypass defects of D-glucose transport and metabolism in the islet B-cell and, hence, improve proinsulin biosynthesis and insulin release in non-insulin-dependent diabetes mellitus.