Abstract:

Objective To observe the expression of metabotropic glutamate receptor (mGluR) 1, 4, 7 in CA1 region of hippocampus in rats with pilocarpine-induced temporal lobe epilepsy. Methods Fifty-six SD rats were randomly divided into control group, status epilepticus (SE) 2 h group, SE 12 h group, SE 24 h group, SE 72 h group, SE 7 d group and SE 14 d group, with 8 rats in each group. Temporal lobe epilepsy models were established in SE 2 h group, SE 12 h group, SE 24 h group, SE 72 h group, SE 7 d group and SE 14 d group by intraperitoneal injection of 325 mg/kg pilocarpine, and rats in control group were injected with same amount of normal saline. RT-PCR and immunohistochemistry were employed to detect the expression of mGluR1, 4, 7 mRNA and mGluR1 protein in CA1 region of hippocampus in each group. Results It was revealed by RT-PCR that the expression of mGluR1 mRNA was significantly lower in SE 24 h group than that in control group, while the expression of mGluR1 mRNA was significantly higher in SE 7 d group than that in control group (P<0.05). There was no significant difference in the expression of mGluR4 mRNA among groups (P>0.05). The expression of mGluR7 mRNA in SE 12 h group, SE 24 h group, SE 72 h group and SE 14 d group was significantly lower than that in control group (P<0.05). Immunohistochemical examination demonstrated that mGluR1 protein mainly existed on cell membrane, and the changes of expression of mGluR1 protein were in line with those of mGluR1 mRNA. Conclusion mGluR 1, 4, 7 may be involved in the pathogenesis of intractable temporal lobe epilepsy.

Key words: metabotropic glutamate receptor, pilocarpine, mRNA, epilepsy animal model