Effect of aging on brain respiration and carbohydrate metabolism of CBF1 mice

Brain slices of mice (strain CBF1) were used to study the effect of aging on cerebral cortex respiration and metabolism. Young animals (average age 6 months) were compared with old animals (average age 34 months). Metabolism was measured at a normal temperature (37 degrees C) and under hyperthermic stress (40 degrees C). The brain slices were incubated with 14C-glucose under standard conditions with the following parameters being measured: oxygen uptake, 14CO2 production, glucose utilization, and lactate and pyruvate formation. At the normal temperature, there were significant age-associated decreases in oxygen uptake and 14CO2 production but the other parameters were unchanged. At hyperthermic conditions there were significant age-associated decreases in oxygen uptake, 14CO2 production, lactate production, and glucose utilization. Also, in the hyperthermia study, all values were raised from control study values (37 degrees C) with old animals showing smaller increases in glucose utilization and lactate formation. These findings indicate the dysfunction of a number of metabolic pathways in the aged animal.