Key enzymes of glycolysis in rat brain: effects of single and repetitive treatment with dihydroergotoxine (Redergin).

The activities of hexokinase, phosphofructokinase and lactate dehydrogenase were measured in the brain of Lewis rats that were 75 days, 6 months and 12 months old. During this period (75--360 days) the activity of hexokinase declines about 5-fold, that of lactate dehydrogenase increases 2-fold, while phosphofructokinase activity is unchanged. Dihydroergotoxine treatment (25 days, 1 mg/kg body weight daily) counteracts these changes. It is concluded that repeated treatment with dihydroergotoxine increases capacity of glycolytic pathway and decreases the capacity of pyruvate to lactate conversion, which could be otherwise excessive in senescent brains under certain pathological conditions.