EFFECT OF STARVATION UPON THE ANOMERIC SPECIFICITY OF GLUCOSE-INDUCEDINSULIN RELEASE

The effects of the anomers of D-glucose (3.3 mM) upon both insulin and glucagon secretion were examined in the isolated perfused pancreas fr om fed rats and animals starved for 2 days. The basal insulin release recorded in the presence of L-leucine (10.0 mM) was not significantly affected by starvation, whilst the basal glucagon output was almost th rice higher in starved than fed rats. In both starved and fed rats, al pha-D-glucose was more potent than beta-D-glucose in stimulating insul in output. There was a trend, however, towards a lesser anomeric diffe rence of insulin output in starved than fed rats. The inhibitory actio n of D-glucose upon glucagon output was significantly impaired in star ved rats but failed to display any obvious anomeric preference. These findings support the view that the effect of D-glucose upon glucagon r elease is not tightly related to the insulinotropic potential of the h exose. Moreover, the present data indicate that the anomeric perturbat ion of glucose-stimulated insulin secretion often encountered in situa tions of B-cell glucotoxicity cannot be solely ascribed to a decreased rate of D-glucose utilization by the B-cell, as indeed observed in st arvation.