Abstract:

[Abstract]   Objective   To investigate the effects of astragalus injection on the morphology and expression of Apaf-1
in hippocampal neurons after cerebral ischemia reperfusion in rats.   Methods   The male SD rats were randomly divided into 3groups, sham-operated group, cerebral ischemia-reperfusion group (reperfusion group) and astragalus injection intervention group (experiment group). The global cerebral ischemia-reperfusion rat model was established by Pulsinelli four-vessel occlusion method. The astragalus injection group was intraperitoneally injected with astragalus6mL/kg,30mins before surgery and repeated every24h. Rat brains were removed24h after reperfusion in each group. HE staining was used to observe the pathological changes of the hippocampal neurons under the light microscope. The ultrastructural changes of hippocam?pal neurons were observed by transmission electron microscopy. Immunohistochemistry and Western blot methods were used to measure the expression of apoptotic protease activating factor-1(Apaf-1) protein.   Results   Compared with sham-operated group, nuclear and mitochondrial damage was found in reperfusion group, and the expression of Apaf-1protein increased obviously in hippocampus（Immunohistochemistry result:0.024±0.001vs0.109±0.011;Western blot result: 0.270±0.018vs0.894±0.072, P＜0.01). Compared with reperfusion group, the damage in nuclear and mitochondria was relieved obviously in experiment group, and the expression of Apaf-1protein in hippocampus was significantly decreased (Immunohistochemistry result:0.048±0.005;Western blot result: 0.392±0.046, P＜0.01).   Conclusion   Astragalus injection can reduce pathological damage of hippocampal neurons after cerebral ischemia and reperfusion in rats, and the mechanism is related with inhibiting of Apaf-1protein.

Key words: reperfusion injury, astragalus membranaceus, hippocampus, apoptosis, Apaf-1