“Rapid Eye Movement sleep deprivation of rat generates ROS in the hepatocytes and makes them more susceptible to oxidative stress”

Abstract

AbstractBackgroundRapid Eye Movement sleep deprivation (REMSD) of rats causes inflammation of the liver and apoptotic cell death of neurons and hepatocytes. Studies also suggest that REMSD are involved with muscle injury, cardiac injury and neurodegerative diseases.Objective and methodsThe aim of this research was to determine whether REMSD of rats would generate reactive oxygen species (ROS) and create oxidative stress in the hepatocytes. We selectively deprived the rats from REM sleep using the standard flower pot method.ResultsWe observed that when rats were subjected to REMSD, the levels of ROS in the hepatocytes increased with the increase in the number of days of REMSD by ∼265%, but it returned towards normal levels after recovery sleep for 5 days (∼36%) compared to controls. Nitric oxide synthase (iNOS) gene and protein was found elevated in hepatocytes in response to REM sleep loss as confirmed by real time PCR and western blot analysis compared to controls. The level of nitric oxide (NO) also increased by ∼ 675% in the hepatocytes of REMSD rats as compared to that of control group of animals.DiscussionWe have analyzed the oxidative stress generated and potentiation of hepatocytes against oxidative stress in response to REMSD. Since, REM sleep is known to play an important role for survival of most animals and has important role in maintenance of body physiology. Hence, our findings that loss of REM sleep in hepatocytes of rats can affect the ROS levels and induce iNOS & NO circulation, while making them more susceptible to oxidative stress assumes significance.Highlights of the studyWe observed elevated levels of ROS in the hepatocytes of REM sleep deprived rats.The hepatocytes of REMSD group of rats were found more susceptible to oxidative stress than that of control groups.We found increased expression of iNOS gene and nitric oxide synthase protein in the hepatocytes of REMSD rats.We observed that nitric oxide levels in the hepatocytes of REM sleep deprived rats increased positively with days of REMSD, but returned to its normal levels after 5 days of recovery sleep.