| Objective: To investigate the protective effect of pretreatment with the platelet-activating factor(PAF)receptor antagonist ginkgolide B(BN52021)on brain injury after seizure in developing rats and its mechanism.Methods: Eighteen 21-day-old male SD rats were randomly divided into 3 groups: control group,pentylenetetrazole(PTZ)group,and PTZ +5mg/kg BN52021 group,with 6 rats in each group.The seizure model of developing rats was made by intritoneal injection of pentylenetetrazol(PTZ).The success standard of the model should reach Racine gradeⅣ-Ⅴ.The rats in the control group were only injected with normal saline,and BN52021(5 mg/kg)were injected intraperitoneally 30 minutes before PTZ induced seizures.24 hours after seizure,the rats were killed and the hippocampal tissues were isolated.Hematoxylin-eosin(HE)staining was used to observe the pathomorphological changes of brain tissue;Western Blot(WB)was used to detect the protein expressions of p-JNK,p-p38 and Bcl2 in hippocampal tissue;Fluorescence quantitative reverse transcription polymerase chain reaction(q RT-PCR)was used to detect the expression of p38,JNK and Bcl2 m RNA in hippocampal tissue.Results: 1.Compared with the PTZ group,the PTZ+5mg/kg BN52021 pretreatment group had significantly lower levels of seizure(p<0.05)and prolonged latency(p<0.05);2.After hematoxylin-eosin(HE)staining,neuronal necrosis(nuclear pyknosis)and cell edema were observed in PTZ group,while neuronal necrosis(nuclear pyknosis)and cell edema were significantly alleviated in BN52021 drug pretreatment group;3.WB: Compared with the control group,the protein expressions of p-p38 and p-JNK in the PTZ group were significantly increased(p<0.05),and the protein expression of Bcl2 was significantly decreased(p<0.05);compared with the PTZ group,PTZ+5mg/kg BN52021 pretreatment histone expressions of p-p38 and p-JNK were significantly decreased(p<0.05),and Bcl2 protein expression increased significantly(p<0.05);4.q RT-PCR: The expressions of p38 and JNK m RNA in PTZ group were significantly higher than that in control group(p<0.05),and the expression of Bcl2 m RNA was significantly lower(p<0.05);The expressions of p38 and JNK m RNA in PTZ+5mg/kg BN52021 pretreatment group were significantly lower than that in PTZ group(p<0.05),and the expression of Bcl2 m RNA was significantly higher(p<0.05);5.Correlation analysis: The protein expression levels of p-p38 and p-JNK in the hippocampus of PTZ-induced rat seizure model were significantly positively correlated with the seizure grade(r=0.910,p<0.05;r=0.923,p<0.05).The expression levels of p38,JNK m RNA were significantly positively correlated with the seizure grade(r=0.799,p<0.05;r=0.823,p<0.05),and the Bcl2 protein was significantly negatively correlated with the seizure grade(r=-0.925,p<0.05),but there was no significant difference in the negatively correlation between Bcl2 m RNA and the seizure grade(r=-0.656,p>0.05).Conclusion: Ginkgolide B pretreatment can up-regulate the expression of anti-apoptotic protein Bcl2,which may play a protective effect on postseizure brain injury by inhibiting p38 and JNK signaling pathways. |
