Neurotoxic effect of Monosodium glutamate on the Circadian Rhythms of Lipid Peroxidation and Antioxidants in Rats under Constant Light

Monosodium glutamate (MSG) was administrated subcutaneously to wistar rats for 60 days and circadian rhythms of thiobarbituri c acid reactive substances (TBARS) and antioxidants such as superoxide dismutase (SOD), reduced glutathione (GSH), catalase, glutathione peroxidase (GP X ) and Vitamin-E were studied. Advanced acrophase of TBARS and delayed acrophase of antioxidants were found in experimental groups as compared with control rats. Constant light exposed rats showed increased mesor of TBARS and decreased mesor of antioxidants. Ampiltude and mesor values of these rhythms were found to be altered in experimental group rats. Glutamate levels in the brain were found to be significantly increased in MSG treated rats. Hence, we hypothesised that the altered biochemical rhythms in MSG treated rats could be due to modulating transmission in several areas in brain, including retinohypothalamic tract and suprachiasmatic nucleus.