Variations in (Na+ + K+)-ATPase and Mg2+-ATPase activity of the ground squirrel brain during hibernation.
1. The specific activity of brain (Na+ + K+)-ATPase and Mg2+ -ATPase of the ground squirrel (Spermophilus richardsonii) is significantly increased after long-term hibernation. 2. The markedly non-linear thermal dependence of (Na+ + K+)-ATPase is unchanged during hibernation whereas the near linear thermal dependence of Mg2+-ATPase undergoes minor alteration after prolonged hibernation. 3. The sensitivity of (Na+ + K+)-ATPase to inhibition by ouabain is significantly decreased after 100 days of hibernation as is both the rate and amount of [3H]-ouabain binding. 4. These changes may be related to alteration in the phospholipid matrix of the membrane rather than alteration in the protein structure of the enzyme.
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D006605:Hibernation; D010042:Ouabain / Q000494:pharmacology; D012589:Sciuridae / Q000378:metabolism*; D012621:Seasons; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics
D010042:Ouabain; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase