Early changes in glucose metabolism in the cerebrum of senescence accelerated mouse: involvement of glucose transporter.

The rate of 6-[14C]D-glucose oxidation in cerebral cells of SAMP8, a substrain of senescence accelerated mouse, was investigated in vitro. The production of 14CO2 in dissociated intact brain cells prepared from the cerebrum of 4-8-week-old SAMP8 was higher than that of age-matched SAMR2 as a control mouse, while no difference between these two strains was observed in the production of 14CO2 in the cerebral homogenates. These results indicated that the increased metabolism of glucose in SAMP8 might be associated with the glucose transport system across the cell membrane. Therefore, 2-deoxy-D-glucose (2-DG) uptake into the brain cells and cytochalasin B (CB) binding to cerebral crude membranes were examined. Both the 2-DG uptake and the CB binding in SAMP8 were much greater than in SAMR2. Furthermore, the increased CB binding in SAMP8 was seen only in the cerebral cortex of 4- to 8-week-old mice, and neither in other regions of the cerebrum nor in other aged mice (2-week- and 40- to 48-week-old mice). These results suggest that the transient overproduction of the glucose transporter protein in the cerebral cortex is involved in the increased glucose metabolism in 4- to 8-week-old SAMP8.