Article révisé par les pairs
| Résumé : | The knowledge that the anomerization of α- and β-D-glucose 6-phosphate is extremely rapid has long been considered as evidence against the view that the metabolism of this hexose-phosphate in the intact cell might involve anomeric regulation by stereospecific enzymes. In the present study, isolated hepatocytes prepared by collagenase digestion of livers removed from fed albino rats were incubated for 5 min at 37°C in the presence of the α- or β-anomer of D-[2-3H]glucose or D-[5-3H]glucose. In both cases, the utilization of the α-anomer exceeded that of the β-anomer. Thus the production of 3H2O from α-D-[2-3H]glucose represented 148.1 ± 9.5 percent of the mean value found with β-D-[2-3H]glucose (100.0 ± 13.5 percent), and the value recorded with α-D-[5-3H]glucose amounted to 158.1 ± 8.7 percent of that found with β-D-[5-3H]glucose (100.0 ± 11.1 percent). These results extend to hepatocytes the knowledge that the metabolism of D-glucose displays anomeric specificity in intact cells, as previously documented in both normal and tumoral rat pancreatic islet cells and in rat erythrocytes. |
