环孢素A抑制炎症改善大鼠脑缺血神经功能

Cyclosporine A inhibits inflammation and improves the neurological function in a rat model of cerebral ischemia reperfusion

目的：探讨环孢素A对大鼠脑缺血再灌注损伤的保护及急性期后的神经功能改善作用。方法250~280g成年雄性SD大鼠52只，随机分为假手术组（A组，n=6），PBS对照组（B组，n=23），10mg/kg环孢素A干预组（C组，n=23）。用线栓法建立大鼠脑缺血再灌注模型，术后C组每天给予环孢素A10mg/kg皮下注射，B组注射等量的PBS溶液。分别于模型建立后第3、7、14、21、30天采用改良神经功能缺损评分（modified neurologi？cal severity scores,mNss）评价神经功能缺损程度，并在第3天取脑组织进行三苯基氯化四氮唑（Triphenyltetrazoli？um Chloride，TTC）染色计算脑梗死体积，第3、30天取脑组织冰冻切片后用免疫荧光检测梗死灶周围活化的小胶质细胞数量，缺血周围区神经元数量，第30天检测梗死灶周围神经胶质细胞的数量，并比较各组间的差异。结果 C组再灌注后第3天（P=0.003）、第7天（P=0.011）、第14天（P=0.000）、第21天（P=0.003）、第30天（P=0.004）的改良神经功能缺损评分均低于B组评分；第3天的脑梗死体积低于B组的体积（P＜0.001）；第3天（P〈0.001）、30天（P=0.017）梗死灶周围神经元存活数量均多于B组的数量；第3天（P＜0.001）、30天（P＜0.001）梗死灶周围活化的小胶质细胞数量明显少于B组的数量；第30天梗死灶周围的星形胶质细胞数少于B组的数量（P=0.024）。结论环孢素A能促进大鼠脑缺血再灌注急性期后的神经功能恢复，机制可能是抑制梗死灶周围活化的小胶质细胞及星形胶质的过度增生。

Objective To explore the neuroprotective effect of cyclosporine A against cerebral ischemia in a rat model of cerebral ischemia reperfusion. Methods Fifty-two adult male SD rats, weighted 250-280 gram, were randomly divided into three groups： the sham group （group A, n=6）, PBS control group （group B, n=23） and cyclosporine A group （group C, n=23）. Group C received hypodermic injection of cyclosporine A 10mg/kg daily after surgery and group B re-ceived equal volume of PBS instead. Modified Neurological Severity（mNss）scores were used to assess the neurological deficits at 3, 7, 14, 21 and 30 days following cerebral ischemia. The infarct volume were measured 3 days after reperfu-sion. The neurons, reactive microglia and astrocytes around the infract area were detected by immunofluorescence at 3 and 30 days after surgery. Results Modified Neurological Severity scores were significantly lower in group C than group＆nbsp;B at the third（P=0.003）,seventh （P=0.011）,Fourteenth （P=0.000）,twenty-first （P=0.003） and thirtieth （P=0.004） days after surgery. cyclosporine A reduced infarct volume, reactive microglia and astrocytes while increased survived neurons （P〈0.001） in ischemic penumbra 3 and 30 days after reperfusion （all P〈0.001）. Conclusion Continuous injection of cyclosporine A not only protects neurons against ischemia damage but also improves neurological functional recovery af-ter acute stage of damage, possibly through reduction of reactive microglia cells and proliferation of astrocytes.