中文摘要：

目的研究大鼠脑外伤后溶酶体酶cathepsin—B和-D是否被激活及其不同时段表达变化。阐述其与凋亡执行因子caspase-3表达的关系，并探讨对脑外伤诊断及形成时间的意义。方法采用自由落体打击法建立脑外伤动物模型，并对模型及对照样本进行免疫荧光、双标和激光共聚焦检测．结果用SPSS10．0软件处理。结果脑外伤后1h cathepsin—B表达即增加，4—8d达高峰，脑外伤后32d仍处于高表达水平；cathepsin—D的表达于脑外伤后12h增加，4～8d达高峰，32d的表达仍然高于12h的表达水平。脑外伤初期，cathepsin—B和-D阳性细胞与caspase-3阳性细胞重叠较少，脑外伤后6h开始增加。32d仍然有很多阳性细胞重叠。结论脑外伤后cathepsin—B和-D被激活。其激活在脑外伤早期可能抑制细胞凋亡执行因子caspase-3的激活，之后（6h后）则与caspase-3起协同作用，共同促进细胞死亡；cathepsin—B和-D表达的时程变化对于脑外伤的法医学诊断和中晚期的时间推断有参考意义。

英文摘要：

Objective To study the expression of cathepsin-B and-D in different time point after traumatic brain injury. Methods Traumatic brain injury （TBI） model was established on rats, cathepsin-B and cathepsin-D immunofluorescence staining and confocal microscope analysis were performed. Positive cells were counted by confocal microscope and image analysis techniques were used to determine the morphological changes in each group. Results Immunofluorescence staining results showed that cathepsin-B was activated 1 hour after TBI while cathepsin-D was not activated until 12hour after TBI. Both of them got to their peak during 4 to 8days, and kept a high level of activating 32days after TBI. Cathepsin-B and -D positive cells did not merge with caspase-3 positive cells until 6 h after TBI. Conclusion Cathepsin-B and-D could be the diagnostic markers of TBI and can estimating time course of latteral TBI. They blocked caspase-3 activation at the beginning period after TBI and started to promote cell death with caspase-3 6h after TBI.