Effect of 7β-Hydroxycholesterol on Glutamate Transporters Expression and Its Mechanism in Hippocampus in Rats of Post-traumatic Epilepsy

Objective:To study the effect of 7β-hydroxycholesterol(7β-OHCH) on glutamate transporters expression and its mechanism in hippocampus of post-traumatic epilepsy rat model.Methods:The models of traumatic epilepsy were established by ipsilateral amygdalar injection of 15 μl FeCl_3(100 mmol/L) into 105 Sprague-Dawley(SD) rats.They were randomly divided into control group(group A),model group(group B) and 7β-OHCH-treated group(group C).Glial febrillary acidic protein(GFAP) and glutamate transporters mRNA expression in hippocampus tissues,animal behavior and electroencephalogram were investigated over the 30 days following injection.Results:The control rats had no significant behavior change.The rate of frequent epileptiform behavior in group B and group C was 94.2% and 74.3% respectively at 30th day after operation(P0.05).Group A persisted normal basic electroencephalogram in which alpha and beta waves were main rhythm during the whole experimental time.Group B and C developed spike wave,spike and s1ow wave complex and sharp wave that were coincided with seizures.GFAP immunoreactivity was significantly increased in the hippocampus of group B,but in group C GFAP immunoreactivity was not detectable at 30th day(P0.01).Compared with group A,the expression of three glutamate transporters mRNA levels in hippocampi in group B had all ascended at first and descended at last,but at 30th day after administration,GLAST mRNA was returned to basal level,GLTl mRNA was lowered to normal level,and EAACl mRNA was significantly up-regulated.The expression of EAACl mRNA had no change,but GLAST and GLTl mRNA up-regulated significantly in group C as compared with group B(P0.05).Conclusion:7β-OHCH could be beneficial for the treatment of post-traumatic epilepsy by inhibiting the gliosis and up-regulating the expression of GLAST and GLTl mRNA in hippocampus tissues.