[ATPase and acetylcholinesterase activity of the brain in hypothermia].

Short-term hypothermia, caused by cooling of rats down to 20 degrees, decreased distinctly the Na+, K+-ATPase activity in brain homogenates incubated at 37 degrees and did not affect the enzyme activity in the homogenates incubated at 20 degrees. The longer hypothermia (2 hrs at 20 degrees) did not affect the Na+, K+-ATPase activity at 37 degrees (during incubation) and decreased the enzymatic activity in homogenates of middle brain and diencephalon at 20 degrees during the incubation. Contrary to Na+, K+-ATPase, the activity of acetylcholinesterase was markedly increased in brain tissues of rats with hypothermia (irrespective of the temperature of incubation) as compared with control animals.