Energetic metabolism in mouse cerebral cortex during chronic hypoxia.
We measured the activities of Na(+)K(+) ATPase and of enzymes of the glycolytic pathway, Krebs cycle, and the respiratory chain in cerebral cortex of mice exposed to chronic hypoxia for three weeks and compared their values with those of sea level controls. There were no differences in Na(+)K(+) ATPase activity or in the activity of glycolytic enzymes. In the Krebs cycle, a 66% increase of succinate dehydrogenase activity was found due to a lower Km. In contrast, respiratory chain cytochrome oxidase activity was reduced by 12% in mice exposed to hypoxia. This suggested that the metabolic demand would be satisfied despite the respiratory chain depression (cytochrome oxidase), probably due to anaerobic energy production within the mitochondria (succinate dehydrogenase).
Laboratorio de Neurociencias, Universidad Peruana Cayetano Heredia, Lima, Peru. rcaceda@emory.edu
R
R
Cáceda
J L
JL
Gamboa
J A
JA
Boero
C
C
Monge-C
A
A
Arregui
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D002908:Chronic Disease; D002952:Citric Acid Cycle; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D002534:Hypoxia, Brain / Q000378:metabolism*; D008297:Male; D051379:Mice; D008928:Mitochondria / Q000201:enzymology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism
D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV; D000254:Sodium-Potassium-Exchanging ATPase