| Objective:To investigate the effects of ephedrine on hippocampal cell apoptosis and impact on learning and memory ability after hypoxia-ischemia brain injury in neonatal rats.Methods:All rats were randomly divided into 3 groups: treatment with ephedrine group,control group,and sham group. Rats in ephedrine group and control received hypoxia-ischemia brain injury. Rats in ephedrine group were treated with ephedrine in doses of 1.5mg·kg-1 I.P. at 5 min after reoxygenation,once a day for 7 days in total (n=30). Rats in control group were given the same volume of saline (n=30). The rat pups of sham group were treated separated the right common carotid,but not ligated and they were not exposed to hypoxia (n=30). At each time interval of 6h,12h,1d,3d,7d after hypoxia,expression of Bcl-2 and Bax were detected in the hippocampal region by immunohistochemistry. At 4 weeks after surgery, behavioral changes in the remaining rats were tested by Morris water maze. Results:1. Control group: the structure of brain tissue is not clear,and neuronal necrosis or pyknosis in hippocampal region was apparent with the proliferation of glial cells obviously. Ephedrine group: Dense neurons were present in the right cerebral cortex and hippocampal area, without significant proliferation of gliocytes. Sham operation group: the structure of brain tissue is clear,the edges of cells were normal. The nuclei were present,and the nucleolus was obvious.2. The expression of Bcl-2 in the ephedrine group was significantly higher than that of the control group after hypoxic-ischemic,peaked at 1 d (P<0.01) and decreased after 3 days (P<0.05). And the expression of Bax in the ephedrine group was lower than that of the control group and a significant difference was noted at 24 hour after hypoxic-ischemic (P<0.01).3. The average time of escape latency was gradually decreased in each group. However,it is much shorter in sham group and ephedrine group than control group,started from the 2ed day,and the 3rd day. In addition, the frequency platform passing in the ephedrine group and the percentage of swimming distance traveled in the previous target quadrant was significantly greater than the control group (P<0.05).Conclusion:Ephedrine may reduce brain injury and improve learning and memory in hypoxic-ischemic brain injury rats by inhibits neuronal apoptosis in hippocampus. This protection may be associated with increased cellular anti-apoptotic protein (Bcl-2) levels and decreased pro-apoptoic protein (Bax).PART TWO EFFECTS OF PUERARIN ON LEARNING AND MEMORY AFTER HYPOSIC-ISCHEMIC IN NEONATALObjective:To investgate the the effects of Puerarin on the espression of BDNF, Bax,caspase-3 in hippocampal cell and impact on learning and memory ability after hypoxia-ischemia brain injury in neonatal rats.Methods:A total of 48 7-day-old (P7),neonatal,Sprague-Dawley rats of clean grade were randomly divided into 3 groups: treatment with puerarin group, control group,and sham group. Rats in puerarin group and control received hypoxia-ischemia brain injury. Rats in puerarin group were treated with Puerarin in doses of 50 mg·kg-1 I.P. at 5 min after reoxygenation,once a day for 7 days in total. Rats in control group were given the same volume of saline The rat pups of sham group were treated separated the right common carotid,but not ligated and they were not exposed to hypoxia. 1 week after hypoxia,expression of BDNF,Bax,caspase-3 were detected in the hippocampal region by immunohistochemistry. At 4 weeks after surgery,behavioral changes in the remaining rats were tested by Morris water maze.Results:1. 1 week later,the expression of BDNF in the puerarin group was significantly higher than that of the control group after hypoxic-ischemic (P<0.05);and the expression of Bax and caspase-3 in the puerarin group was lower than that of the control group (P<0.01).2. The average time of escape latency in puerarin is much shorter than control group(P<0.05). In addition,the frequency platform passing in the puerarin group and the percentage of swimming time traveled in the previous target quadrant was significantly greater than the control group(P<0.05).Conclusion:Puerarin may reduce brain injury and improve learning and memory in hypoxic-ischemic brain injury rats. This protection may be associated with increased BDNF levels and decreased pro-apoptoic protein (Bax) and caspase-3. |
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