Effects of the polyacetate esters of nutrient and nonnutrient monosaccharides on 45calcium efflux and insulin release from perifused rat pancreatic islets.

Abstract

The polyacetate esters of selected nonnutrient monosaccharides represent potential tools for either stimulation of insulin release in noninsulin-dependent diabetes or inhibition of insulin secretion in hyperinsulinemic syndromes. The polyacetate esters of several monosaccharides were recently shown to display greater nutritional value or biological efficiency than the corresponding unesterified carbohydrates. The effects of seven polyacetate esters of monosaccharides, all tested at a 1.7-mM concentration, on both 45Ca efflux and insulin release were investigated in prelabeled rat pancreatic islets perifused in the presence of 10.0 mM succinic acid dimethyl ester. Both alpha-D-glucose penta-acetate and, to a lesser extent, beta-L-glucose penta-acetate stimulated insulin release. Inversely, alpha-D-galactose penta-acetate, but not beta-D-galactose penta-acetate inhibited insulin secretion evoked by succinic acid dimethyl ester. Esters of carbohydrates which are inhibitors of D-glucose metabolism, such as D-mannoheptulose hexa-acetate and the two anomers of 2-deoxy-D-glucose tetra-acetate also enhanced insulin output, with a preference for the alpha-anomer of 2-deoxy-D-glucose tetra-acetate. Only those esters with positive insulinotropic action augmented 45Ca efflux from the prelabeled islets.