Effects of chronic administration of dextroamphetamine on enzymes of energy metabolism in regions of the rat brain.
In the present study the effects of chronic administration of dextroamphetamine on energy metabolism in the brain of the rat were examined. The enzymes studied were: hexokinase (soluble and particulate forms), phosphofructokinase, pyruvate kinase, lactate dehydrogenase, citrate synthase, NAD+ and NADP+-dependent isocitrate dehydrogenases, succinate dehydrogenase and malate dehydrogenase. All the activities of the enzymes were assayed in four regions of the brain of the rat (cerebellum, medulla oblongata and pons, cererbral cortex and diencephalon). Rats were injected intaperitoneally once daily with dextroamphetamine for 20 consecutive days. The initial dose was 5 mg/kg/day and the dose was then increased by 1 mg/kg/every 5 days up to a total of 8 mg/kg/day on days 16-20. In the glycolytic enzymes a reduction of the activity of phosphofructokinase was found in the diencephalon and an increase of the activity of pyruvate kinase and lactate dehydrogenase in the diencephalon and medulla oblongata and pons, respectively. Citrate synthase was the only enzyme in the Krebs' cycle affected by chronic administration of dextroamphetamine. The results presented here show that chronic administration of dextroamphetamine produced important changes in some enzymes of glycolysis and the Krebs' cycle in the brain of the rat.
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D003913:Dextroamphetamine / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D008297:Male; D010088:Oxidoreductases / Q000378:metabolism*; D010770:Phosphotransferases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D010088:Oxidoreductases; D010770:Phosphotransferases; D003913:Dextroamphetamine