| Objective:(1) By building the lithium-pilocarpine induced status epileptics(Li-Pilo SE) model,to observe the behavioral performance on this model rats after the intervention on scorpion venom(SV) and valproic acid(VPA), to study the anti-epileptic effects comparatively; (2) To observe the dynamic changes of S-100(3 mRNA in hippocampus after lithium-pilocarpine induced SE on male adult rats; (3) To investigate the influence of S-100(3 mRNA expression on this model after the intervention of SV,VPA and explore the possible anti-epileptic mechanism. Methods:(1) 12 cleaning degree normal male SD rats were enrolled into group A(normal control group,n=6) and group B(SV control group,n=6); All the Li-Pilo SE model rats were enrolled into three groups randomly:group C(Model only group, n=20),group D(VPA treating group, n=20), group E(SV treating group, n=20). Group C, D, E were further divided into 5 subgroups based on the different sacrifice time:at 6thh, 24thh,2thd,3thd and 7thd after SE induction,4 rats in each subgroup. (2) The group A, C were intragastric administrated with normal sodium; the group B,E were given SV(0.3mg·kg-1·d-1); the group D was administrated with VPA(120mg·kg-1·d-1). The behaviors, death status, seizure frequency and severity scale seizure of the rats were monitored within 7 days after intervention; (3) The expression of S-100βmRNA in rat hippocampus were detected by In situ hybridization (ISH) at 6thh,24thh,2thd,3thd,7thd after SE induction in each group. And then, to analyze the discrepancy of these values in each group. Results:(1) Behavioral observation results of the Li-Pilo SE model rats:①74.23% of the Li-Pilo model rats was induced SE successfully;②During the 7 days observation period, most of the rats in model group seizured over gradeⅢ～Ⅴ,and seizured frequently; but no seizure and SE were found in normal control group and SV control group;③Compared with model group, the total number of seizures and seizure level were lower in SV treating group and VPA treating group during the observation period(P<0.05);④Although SV treating group had higher seizure frequency to VPA treating group(P<0.05), no significant difference between the two groups(P> 0.05). (2) Dynamic changes of S-100βmRNA-positive cells(PC) in Li-Pilo SE model rats hippocampus after intervention in each group:①The number of S-100(3 mRNA-PC began to increase after SE induction in hippocampus in control group, especially in CA1 and DG regions.②The number of S-100(3 mRNA-PC began to increase at 6thh after intervention in hippocampus in model group and VPA,SV treating group; each group had no significant difference to the other group(P>0.05). (3)At 24thh after intervention, the expression of S-100βmRNA-PC in VPA,SV treating group had reached the peak, however, model group, less than peak performance to continue to increase. Each group had no significant difference to the other group(P>0.05). The PC in model group(in CA1 regions), VPA treating group(in CA1,DG regions) and SV treating group(in CA1,CA3,DG regions) were obviously higher than 6thh (P<0.05).④The expression of S-100βmRNA-PC began to decline gradually at 2thd after intervention. The PC in VPA treating group had no significant difference compare with model group(P>0.05). The PC in SV treating group(in CA1,CA3,DG regions) declined greatly compare with model group and VPA treating group(P<0.01). VPA treating group decline gentlely(P>0.05) while SV treating group(in CA1,DG regions) decline greatly(P<0.05) compared with the expression at 24thh. Model group had no significant difference compared with the 24thh(P>0.05).⑤At 3thd and 7thd after intervention, the PC in VPA treating group in all regions declined greatly compare with model group(P<0.01). The PC in SV treating group declined greatly compare with model group and VPA treating group(P<0.01).Model group reached the peak at 3thd after intervention,compared with VPA,SV treating group, the time to peak delayed. The expression of S-100βmRNA-PC in VPA, SV treating group had no significant difference compared with the previous time point(P> 0.05).⑥At the end of 7d's observation period, no group recovered to normal,but the expression in VPA,SV treating group was less significantly than the model group(P<0.01). Model group had no recovery trend, continued to increase. Conclusion:(1) SV has significant anti-epileptic effects on Li-Pilo SE rats, compared with placebo, it has significant effects on reducing the level of seizures and seizure frequency; (2) At the acute observation on Li-Pilo SE model, SV has no significant difference to VPA in reducing seizure scale, but the intervention doses of SV in this study has weaker effect to VPA in reducing seizure frequency; (3) SV may has more advantages to VPA in prevention of neuronal injury, prevent the formation of gliosis and promote axon growth; (4) After the intervention of VPA and SV, the expression of S-100βmRNA-PC in all regions changed over time:increased in the beginning 6thh, reached the peak at 24thh or so, and was gradually reduced thereafter. However, model group had not such changes,it reached the peak at 3thd, then it continued to show a slow upward trend in 7d observation period. Shortly after the seizure that S-100βmRNA changes may reflect the severity of brain injury and prognosis. SV cerebral protection with VPA may play the same role in one of the antiepileptic mechanisms; (5) After the intervention of VPA and SV, the S-100(3 mRNA-PC peaked at 24 hours, while model group reached the peak until 3d. Indicating that the VPA and SV, can make peak time ahead of time, may play earlier cerebral protection; (6) All the Li-Pilo SE model rats after the intervention of VPA,SV, the expression of S-100(3 mRNA-PC in CA1,CA3,DG regions declined greatly, and SV was significantly lower than VPA.Indicating that the main antiepileptic mechanisms that SV to play role of, may not be all the same to VPA, by inhibiting the damage response to nervous system may play a role in SV antiepileptic effect, may be one of the main antiepileptic mechanism. These results suggest that SV intervention dose response in the inhibition of nervous system damage may be superior to VPA; (7) At the end of 7d's observation period, the expression of S-100βmRNA-PC in VPA,SV treating group were not back to normal, although the expression was significantly weaker than the model group, but still stronger than the normal control group. Pathologic damage in hippocampus caused by epileptic agent(lithium-pilocarpine) is sustained or permanent, although reduced the expression of S-100βmRNA to some extent after the intervention of VPA,SV, but could not correct the pathological damage in hippocampus completely during the observation period.
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