Stimulation of insulin release caused by intraduodenal administration of succinic acid methyl esters.

The methyl esters of succinic and glutamic acid are currently under investigation as possible tools for stimulation of insulin biosynthesis and release in non-insulin-dependent diabetes mellitus. The present study deals with the secretory response of the pancreatic B-cell to these esters after intraduodenal administration to anaesthetized rats. The dimethyl ester of succinic acid and, to a lesser extent, its monomethyl ester both increased the plasma insulin concentration, whilst the dimethyl ester of glutamic acid virtuality failed to do so. The stimulation of insulin release, caused by the dimethyl ester of succinic acid, was faster and more pronounced than that evoked by an equimolar amount of glucose. The present study thus reveals that the latter ester, when administered via the gastrointestinal tract, evokes a more brisk and more ample secretory response of the pancreatic B-cell than that evoked by glucose.