ABSTRACT
Objective To explore the effects of Ginkgolide B on the expression of hypoxia inducible factor 1 α (HIF-1α) and P I3K/Akt pathway in the hippocampus of developing rats after pentylenetetrazol(PTZ)-induced status epilepticus,and to investigate the correlation between HIF-1α expression and PI3K/Akt pathway.Methods Ninety-six SD rats aged 21 days were randomly divided into normal saline group(group NS),status epilepticus group (group P),GKB treatment groups (group G+P),GKB +wortmannin treated group (group G+P+W),wortmannin treated group(group P+W).The brain tissue were harvested from the rats at 4 and 8 hours after the inducement,but in the group G+P at 1 h,4 h,8 h,24 h.Immunohistochemistry and Western blot were used respectively to detect HIF-1α and p-Akt protein expression.Results (1) For the group G+P,there were statistical differences in the expression levels of p-Akt protein between 1 h,4 h,8 h and 24 h(P＜0.01),The p-Akt protein reached the peak level at 4 hours (0.85±0.03),there were statistical differences in the expression levels of HIF-1α protein between 1 h,4 h,8 h and 24 h(P＜0.01),the HIF-1α expression reached the peak level at 8 hours(1.00±0.13).(2) The expression of HIF-1α in all the groups at 8 hours time point:the expression levels of HIF-1α in the group P and group G+P were significantly higher than those in the group NS (P＜0.01) and the expression levels of HIF1α in the group G+P were higher than those in the group P(P＜0.01).Using wortmannin,the PI3K/Akt specific inhibitor,HIF-1α protein expression in the group G+P+W and P+W was significantly decreased when compared with the group G+P and P (P＜0.01).(3)The expression of p-Akt in all the groups at 4 hours time point:the expression levels of p-Akt in the group P and group G+P were significantly higher than those in the group NS (P＜0.01) and the expression levels of p-Akt in the group G+P were higher than those in the group P (P＜ 0.01).Using wortmannin,p-Akt protein expression in the group G+P+W and P+W was significantly decreased when compared with the group G+P and P (P＜0.01).Conclusion GKB can activate PI3K/Akt signaling pathway,and the pathway is involved in regulating the expression of HIF-1α.