Differential Effects of Alpha- and Beta-D-Glucose on Insulin and Glucagon Secretion from the Isolated Perfused Rat Pancreas

The efficacy of α and β-D-glucose in causing insulin release and suppressing glucagon release from the isolated perfused rat pancreas was tested. In order to allow simultaneous assessment of the glucose effect on both α and β-cells, the pancreas was continually perfused with a physiological amino acid mixture (10 mM) which provokes glucagonvsecretion and also stimulates the β-cells, provided glucose is present. Under these conditions the α-anomer of D-glucose at 3 and 6 mM proved significantly more potent than the β-anomer in inducing insulin release and in inhibiting glucagon secretion. These data lend further support to the concept that α-cells and β-cells contain glucoreceptors controlling glucagon and insulin secretion and show that certain physicochemical properties of these receptors are alike in both types of cells.