A Study On The Effection Of Baicalin On The Expression Of Kir4.1 And AQP4 In Hippocampal Neurons After Status Epilepticus In Mice

Objective This investigation was performed to explore the neuroprotective mechanism of Baicalin on hippocampal neurons after status epilepticus induced by kainic acid in mice.Methods 60 ICR male mice(weighing 22–28g) were randomly divided into three groups: sham control(n=20), status epilepticus(SE, n=20)and baicalin group(n=20),to which baicalin was administered at doses of 100mg/kg. To establish animal model of status epilepticus, 0.1μg/5μl kainic acid(KA) was injected into the intracerebral ventricle of the mouse.The mice were then received intraperitoneal injection with baicalin(100mg/kg) or vehicle. Hematoxylin and Eosin(HE) staining was used to observe the pathological changes in hippocampus area, Immunohistochemistry and western blot were used to detect the expression of Kir4.1 and AQP4 48 h after SE in mice.Results ①To observe by HE staining: About 48 h after the onset of SE: The structure of hippocampal in Control group remains normal, pyramidal cells subfield with eumorphism, even shading, reddish cytoplasm, blue and relatively clear nucleus. The structure of CA3 area of hippocampal in SE group is obviously abnormal, cells are disordered and deeply blue dyed, appeared shrunken with eosinophilic cytoplasm and triangulated pyknotic nuclei, nucleolus disappeared. Baicalin group has improved significantly compared with SE group. ② Immunohistochemistry: 1) Kir4.1: Immunohistochemistry showed the Sham group had only a few scattered yellow-brown positive cells of Kir4.1, while the SE group can be seen numerous and densely distributed positive cells. Compared with the SE group, the brown granular positive cells of Baicalin treatment group increased significantly and their differences was obvious; 2) AQP4: Immunohistochemistry showed the Sham group had only a few scattered yellow-brown positive cells of AQP4, while the SE group can be seen numerous and densely distributed positive cells. Compared with the SE group, thebrown granular positive cells of Baicalin treatment group reduced significantly and their differences was obvious. ③Western blot: 1) Kir4.1: Western blot showed that the expression of the protein 1evel of Kir4.1 of Sham group were scant, but its increased significantly after status epilepticus(P<0.05). Compared with the SE group, Baicalin could obviously up-regulate the expression of Kir4.1 protein(P<0.05); 2) AQP4: Western blot showed that the expression of the protein 1evel of AQP4 of Sham group were scant, but its increased significantly after status epilepticus(P<0.01). Compared with the SE group, Baicalin could obviously down-regulate the expression of AQP4 protein(P<0.05)Conclusion Our results suggest that baicalin could significantly protect hippocampal neurons after status epilepticus in mice, which might be associated with the up-regulated expression of Kir4.1 and with the down-regulated expression of AQP4.