Modulation by D-glucose anomers of the effect of D-fructose upon 45Ca efflux from prelabelled rat pancreatic islets
- Authors:
- Published online on: October 1, 2003 https://doi.org/10.3892/ijmm.12.4.513
- Pages: 513-515
Metrics: Total
Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )
Abstract
It was recently reported that α-D-glucose is more potent than β-D-glucose in conferring to glucokinase positive cooperativity towards D-fructose. We have now extended pilot experiments to investigate whether a comparable situation prevails in intact rat pancreatic islets in terms of the modulation by the D-glucose anomers of the effect of D-fructose upon 45Ca efflux from prelabelled perifused islets. As expected from the effect of increasing concentrations of equilibrated D-glucose upon 45Ca efflux from the prelabelled islets, D-fructose either decreased or increased 45Ca outflow from islets perifused in the presence of either α- or β-D-glucose. In all cases, the α-anomer of D-glucose affected more markedly than β-D-glucose the cationic response to D-fructose. These findings indicate that the anomeric specificity of the effect of D-glucose upon D-fructose phosphorylation by glucokinase is also operative in intact islets.