Partial inactivation of Na,K-ATPase in cortical brain slices incubated in normal Krebs-Ringer phosphate medium at 1 and at 10 atm oxygen pressures.
Na,K-ATPase (ATP phosphohydrolase EC 3.6.1.3) activity was determined in homogenates of cortical brain slices after incubation in normal Krebs-Ringer phosphate medium at 1 atm oxygen pressure. After 10 min of incubation Na,K-ATPase activity was reduced by approximately 50%. Longer incubation did not cause further change in activity. The presence of 0.1 mM-MnCl2 in the medium offered significant protection, while an excursion to 10 atm oxygen pressure caused further inactivation. Measurements of malonaldehyde levels suggest that the inhibition of Na,K-ATPase is a result of lipid peroxidation. The evidence indicates that brain slices incubated under standard conditions suffer considerable oxidative damage.
D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D003470:Culture Media; D046508:Culture Techniques; D004789:Enzyme Activation; D008054:Lipid Peroxides / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D010100:Oxygen; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013997:Time Factors
D003470:Culture Media; D008054:Lipid Peroxides; D008315:Malondialdehyde; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium; D010100:Oxygen