Effect of paradoxical sleep deprivation on oxidative stress parameters in brain regions of adult and old rats

The present study examined the effects of paradoxical sleep (PS) deprivation on the oxidative stress parameters: lipid peroxidation, superoxide dismutase, glutathione peroxidase, and glutathione in brain regions: cerebral cortex, striatum, hippocampus, thalamus, hypothalamus, and brain stem of adult (8 months) and old (24 months) rats. PS deprivation (96 h) was performed by the classical flower pot technique. PS deprivation did not affect oxidative stress parameters in the striatum of both age groups; and the activity of glutathione peroxidase was not affected in any of the studied brain regions in both age groups. PS deprivation decreased the levels of glutathione only in the hippocampus, thalamus and hypothalamus; the magnitude of decrease was higher in the old than in the adult age group. PS deprivation increased the superoxide dismutase activity in the cerebral cortex and brain stem but reduced it in the hippocampus, thalamus and hypothalamus in both age groups. Increases in the activity were greater in adult animals than in old ones; the decline in the activity was greater in the hippocampus of old animals than in that of the adult ones. Lipid peroxidation was reduced by PS deprivation in the cerebral cortex and brain stem but was elevated in the hypothalamus and thalamus: the magnitude of alteration in the cerebral cortex, brain stem, hippocampus and hypothalamus was higher in adult animals than in old ones. The results showed that oxidative stress was not uniformly affected in all the brain regions. The cerebral cortex and brain stem showed a fall in oxidative stress after PS deprivation; the fall was greater in the adult than in the old animals. However, the oxidative stress was elevated in the hippocampus, thalamus and hypothalamus, and old animals were more severely affected than the adult ones.