不同浓度常压氧对大鼠脑缺血再灌注损伤早期的保护作用

Protective effect of different concentrations of normobaric oxygen in early cerebral ischemic-reper-fusion injury rat model

目的 观察不同浓度常压氧（NBO）对大鼠急性脑缺血再灌注损伤早期的保护作用.方法 将120只大鼠随机分为高、中、低浓度NBO治疗组和模型组,每组再随机分为缺血再灌注3、6、12、24、48、72h6个亚组（n=5）.评价缺血再灌注损伤大鼠吸氧前后神经功能缺损程度,免疫组织化学法检测脑组织半胱氨酰天冬氨酸特异性蛋白酶（Caspase）-9及Caspase-3的表达水平.结果 NBO治疗组大鼠的神经功能缺损评分有不同程度的降低,高浓度NBO组在各时间点（1.40±0.55、1.20±0.45、1.40±0.55、1.20±0.84、1.20±0.84、1.00±0.71）与模型组（2.20±0.45、2.20±0.84、2.20±0.45、2.20±0.45、2.80±0.84、2.60±0.54）比较,差异均有统计学意义（P＜0.05）.高、中、低浓度NBO治疗组Caspase-9及Caspase-3各时间点的表达量均低于模型组（P＜0.05）.结论 高浓度NBO可明显降低急性脑缺血再灌注早期Caspase-9及Caspase-3蛋白的表达,提高大鼠的神经功能,中、低浓度NBO治疗显效时间较高浓度组滞后.

Objective To observe the protective effect of different concentrations of normobaric oxygen （NBO） on rats with acute cerebral ischemia reperfusion in early time.Methods 120 rats were divided randomly into high,medium and low NBO treatment groups and model group.Every group was divided into 3,6,12,24,48,and 72 h subgroups after ischemia reperfusion （n =5 each）.The neurologic impairment scores were assessed in rats before and after oxygen inhalation,and the expression of Caspase-9 and Caspase-3 protein was detecte 4 d by using immunohistochemistry.Results Neurologic impairment scores in NBO treatment groups were decreased to varyoing degrees.There was statistically significant difference beween the high NBO treatment group （1.40 ±0.55,1.20 ±0.45,1.40 ±0.55,1.20 ±0.84,1.20 ±0.84,1.00±0.71） and the model group （2.20 ±0.45,2.20 ±0.84,2.20 ±0.45,2.20 ±0.45,2.80 ±0.84,2.60 ± 0.54） at each time point （P 〈 0.05）.The expression of Caspase-9 and Caspase-3 protein in the high,medium and low NBO treatment groups was lower than in the model group （P 〈 0.05） at each time point.Conclusion The high concentration of NBO could reduce the expression of Caspase-9 and Caspase-3 protein obviously in rats with acute cerebral ischemia reperfusion and enhance the neurological function in early time,and medium and low concentrations of NBO had obvious effect delay as compared with high concentration of NBO.