The insulinotropic action of D-erythrose

Abstract

D-erythrose (5.0 to 20.0 mM) stimulates insulin release. This insulinotropic action of erythrose displays several features in common with that of glucose. First, erythrose (20 mM) causes a shift to the left of the sigmoidal curve relating the secretory rate to the glucose eoncentration, but fails to enhance the maximal response to glucose. Second, the secretory response to erythrose occurs as an early peak followed by a phase of sustained release. Third, erythrose increases the output of lactate from the islets. Last, erythrose inhibits the efflux of 45calcium and favours its accumulation in isolated islets. It is suggested that, whether in response to glucose or erythrose, an increase in glycolytic flux may represent the key process involved in the identification of the secretagogue, a subsequent remodeling of calcium fluxes being apparently responsible for the activation of the insulin-releasing system.

The stimulus-secretion coupling of amino acid-induced insulin release

“…Although these data indicate that insulin release provoked by the combination of L-glutamine and Lleucine shares several features in common with that provoked by D-glucose or other nutrient secretagogues, a striking difference between these two processes should be underlined. Whereas the stimulation of insulin release by most nutrients (e. g. Dglucose, D-glyceraldehyde, D-erythrose, pyruvate, lactate, L-leucine, a-ketoisocaproate, a-ketocaproate; [24][25][26][27][28] is characterized by a biphasic pattern, the enhancement by L-glutamine of L-leucine-stimulated insulin release was a steadily increasing phenomenon. In the pancreas already exposed to Lleucine, no initial secretory peak occurred in response to L-glutamine administration (Fig.…”

Pancreatic islet glucose metabolism and regulation of insulin secretion

“…One of the most potent inhibitors of phosphoglucose isomerase is erythro~e-4-phosphate,~'~ yet glucose usage in islets is claimed to be increased under conditions where this metabolite is likely to be elevated. 47 The weight of evidence indicates that the phosphoglucose isomerase reaction is likely to be near equilibrium under steady-state condtions in islets metabolizing glucose49 and, therefore, is an unlikely site for the regulation of glycolysis in pancreatic islets. Conflicting data have been reported for studies of the equilibrium state of the phosphoglucose isomerase reaction in isolated islets incubated with mannose.…”

Biosynthesis of L-Erythrose by Assembly of Two Key Enzymes in Gluconobacter oxydans

“…It also exhibits inhibitory effect on cancer cells and may be used in treating cancer. 2 2-Deoxy-L-erythrose, a derivative of L-erythrose, possesses anti-HIV activity. 3 Previous reports show that transketolases can produce Lerythrose from glyceraldehyde and a combination of βhydroxypyruvate and glyceraldehyde.…”

“…Several reports show that erythrose possesses a hypoglycemic effect. It also exhibits inhibitory effect on cancer cells and may be used in treating cancer . 2-Deoxy-L-erythrose, a derivative of L-erythrose, possesses anti-HIV activity …”