Influence of N-Phthaloyl GABA on the Circadian Rhythms of Lipid Peroxidation and Antioxidants in Wistar Rats under Constant Light

N-Phthaloyl GABA was administrated daily (50 mg/Kg body weight-i.p) to Wistar rats for 21 days and circadian rhythms of thiobarbituric acid reactive substances (TBARS) and antioxidants such as reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) were studied under constant light (LL) conditions. Delayed acrophase of TBARS and advanced acrophase of antioxidants (GSH, CAT and SOD) were found in LL-exposed  groups as compared with control rats. LL-exposed rats showed increased mesor of TBARS and decreased mesor of antioxidants. Administrations of GABA reversed all the changes in circadian rhythms to the near normal. Since GABA is being involved in conveying dark information to biological clock, exogenous administration of P-GABA might reduce the photic information received by the clock. The exact mechanism is still unclear and further research is needed to elucidate the mechanism(s) involved.