Study of developmental changes on hexoses metabolism in rat cerebral cortex

We have studied the developmental changes of glucose, mannose, fructose and galactose metabolism in rat cerebral cortex. As the animals aged, glucose, mannose and fructose oxidation to CO2 increased, whereas galactose oxidati on decreased. Lipid synthesis from glucose and fructose also increased with age, that from mannose decreased and galactose did not change. Cytochalasi n B, a potent non-competitive inhibitor of sodium-independent glucose trans port, significantly impaired glucose, mannose and galactose metabolism, but had no effect on fructose metabolism. Both galactose or fructose did not c hange, whereas mannose declined the glucose metabolism. Glucose decreased f ructose, galactose and mannose metabolism. Our results show that besides gl ucose, the metabolism of mannose, galactose and fructose present developmen tal changes from fetal to adult age, and reinforce the literature data indi cating that mannose and galactose are transported by glucose carriers, whil e fructose is not.