Increased turnover of Na-K ATPase molecules in rat brain after rapid eye movement sleep deprivation.

It has been shown that rapid eye movement (REM) sleep deprivation increases Na-K ATPase activity. Based on kinetic study, it was proposed that increased activity was due to enhanced turnover of enzyme molecules. To test this, anti-alpha1 Na-K ATPase monoclonal antibody (mAb 9A7) was used to label Na-K ATPase molecules. These labeled enzymes were quantified on neuronal membrane by two methods: histochemically on neurons in tissue sections from different brain areas, and by Western blot analysis in control and REM sleep-deprived rat brains. The specific enzyme activity was also estimated and found to be increased, as in previous studies. The results confirmed our hypothesis that after REM sleep deprivation, increased Na-K ATPase activity was at least partly due to increased turnover of Na-K ATPase molecules in the rat brain. Copyright 2003 Wiley-Liss, Inc.