EFFECTS OF IMMUNOGLOBULIN ON PENTYLENTETRAZOL-INDUCED CONVULSION AND ON C-FOS EXPRESSION OF BRAIN NEUROCYTES IN RAT

Yang L, Zhou Z-S, Hu J, Liu P-C, Ariizumi M-M

Department of Pediatrics China-Japan Friendship Hospital, Beijing, China

Objective: Clinical effect of human immunoglobulin (IGG) on child epilepsy and uptake of IGG into the brain neurocytes has been reported. To explore the action mechanism of IGG, we examined the effect of IGG on c-fos expression in brain neurocytes of PTZ-induced convulsion rats.

Methods: Fifteen male Wistar rats were devided into three groups, that is, group A: non-treated 3; group B: PTZ plus intravenous IGG (IVIG) 6 and group C: PTZ plus normal saline (NS) 6. PTZ 50mg/kg/day was intrapenitoneally injected every day. IVIG 200mg/kg/time and NS same volume as IVIG were intravenouslly injected 2 times a week respectively. Clinical seizure was evaluated by Loscota score. The brains were extirpated under complete ether anesthesia. The c-fos expression was detected by immunohistochemistry staining (ABC method).

Results: Compared with rats of group C the seizures in rats of group B showed obvious longer latencies and marked lower convulsion scores. None of rats died in group B, while 3 of six were dead in group C. In group C latencies of seizures showed a tendency to become short and no obvious change of convulsion scores. In group C c-fos expression was markedly observed in the nucleus of neurocytes in the hippocampus, dentate gyrus, piriform cortex, amygdala, hypothalamus, supurammillary nucleus and temporal cortex, although c-fos expression of group A was detected occasinolly. The c-fos expression significantly decreased at the same region of brain tissues when compared with that in group C (p<0.01).

Conclusion: IVIG inhibited PTZ-induced convulsions as well as c-fos expression. These results indicate that IGG posses the ability to inhibit neurocyte activation on molecular base.

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