Effect of Melatonin on GABA,Glu Content and GAD,GABA-T Activity in Hippocampus of Rats Post-SE Induced by Pilocarpine

Objective To study the biochemical mechanisms of melatonin as anticonvulsant from the neurotransmitter point of view.Methods Model of status epilepticus(SE) was induced by pilocarpine;Observing the changes of γ-aminobutyric acid(GABA),glutamic acid(Glu) content and glutamic acid decarboxylase(GAD),γ-aminobutyric acid-transaminase(GABA-T) activity at 6 h,48 h,72 h,and 7 d in hippocampus of rats after SE was induced.And to observe the effect of melatonin on these changes.Results The level of GABA and GAD activity was significantly lower and the level of Glu was significantly higher in hippocampus post-SE in pilocarpine group than the control(P0.05).GABA-T activity was significantly decreased just at 72 h post-SE(P0.05);At 6 h~7 d post-SE,the GABA content and GAD activity in hippocampus was significantly higher in rats treated with both pilocarpine and melatonin than that in rats only treated with pilocarpine(P0.05).There was no significant difference of Glu content and GABA-T activity between pilocarpine treated group and both pilocarpine and melatonin treated group(P0.05).Conclusions The anticonvulsive effect of melatonin may be due to increasing GAD activity and GABA content.