Melatonin treatment does not prevent decreases in brain glutathione levelsinduced by sleep deprivation

Recent findings from this laboratory revealed that sleep deprivation reduce s total glutathione (GSH) levels in hypothalamus, suggesting an increased v ulnerability to oxidative damage. Since melatonin has been shown to prevent oxidative damage in other experimental situations, the present study teste d the effects of exogenous melatonin on sleep deprivation-induced GSH decre ases. Rats were deprived of sleep for 96 h on small platforms, and melatoni n (10 mg/kg body weight; i.p.) or vehicle was given twice a day. Hypothalam ic GSH levels were significantly reduced in sleep-deprived groups, irrespec tive of melatonin treatment. Indeed, unexpectedly, melatonin treatment resu lted in lower hypothalamic GSH levels in all groups, including cage control s. These results confirm that sleep deprivation reduces hypothalamic GSH an d further indicate that melatonin treatment not only is ineffective in reve rsing this effect but may actually potentiate it. (C) 2000 Elsevier Science B.V. All rights reserved.