中文摘要：

目的：探讨重复性低氧对小鼠脑组织内MMP-2和MMP-9的蛋白表达量及活性的变化。方法：将BALA／C小鼠随机分成常氧对照组（I加）、急性低氧1、2、3、4次组（H1～H4）共5组。应用SDS-PAGE、Western—blot等生化技术，并结合Gel Doc凝胶成像系统，半定量检测5组小鼠大脑皮层和海马组织内MMP-2及MMP-9的蛋白表达量及其活性的变化。结果：①随着低氧次数的增加，小鼠海马组织内MMP-2的蛋白表达量呈现先增后降的趋势，其中H4组MMP-2蛋白表达量的降低显著（P〈0．05，n=6），而小鼠大脑皮层组织内MMP-2的蛋白表达量变化不明显。此外，在海马和大脑皮层组织内均未检测到MMP-2的活性组分；②海马组织内MMP-9的蛋白表达量随重复性低氧次数的增加，其含量也呈现先增后降的趋势，且H1组MMP-9表达量的增高和H4组MMP-9表达量的降低均具有显著意义（P〈0．05）。同样，海马组织内MMP-9活性组分的变化与其蛋白表达量变化趋势一致，与H0组相比．H1组MMP-9活性组分增高和H4组的降低均显著（P〈0．05）。大脑皮层组织内MMP-9表达量及其活性组分在脑低氧预处理过程中均无显著性变化。结论：MMP-2和MMP-9可能在脑低氧预处理过程中具有一定的作用．且提示其蛋白表达量及活性在大脑皮层和海马组织内的差异变化可能与大脑皮层和海马组织对低氧的选择易损性不同有关。

英文摘要：

Aim： To explore the changes of MMP-2/9 ic mice. Methods： The biochemistry techniques of SDS-PAGE, Wprotein expression and excitation in brain of repetitive hypoxestern bolt and Gel Goc Image Analysis System were applied to determine the level of MMP-2 and MMP-9 expression and activation in cortex and hippocampus of mice. The animals were randomly divided into 5 groups： the normal control group （H0）, acute hypoxic （HI, hypoxic exposure once）, repetitive hypoxic groups （H2- H4, repetitive hypoxia for 2--4 runs respectively）. Results： ① the MMP - 2 expression level was increased first then decreased in hippocampus and the significant decrease was found in H4 group（ P〈 0.05, n = 6）, but no significant changes among the 5 groups in cortex. In addition, no activated form of 66 kD MMP-2 had been detected both in hippocampus and cortex. ②Along with the development of brain hypoxic preconditioning, the level MMP-9 protein expression also increased first then decreased gradually in hippocampus, and the significant changes were found both in HI and H4 groups （P〈0.05, n = 7 for each group）. The same trace of changes was also found in the activation of MMP-9 （include 82 and 78 kD forms） in hippocampus, and the significance both in H1 and H4 （P〈 0.05, n = 7 for each group） were detected. However, there was not any significant change in the level of MMP-9 protein expression or activation to be found in cortex. Conclusion： These results suggested that MMP-2 and MMP-9 might play certain role in the development of cerebral hypoxic preconditioning, the different changes of MMP-2/9 protein expression and activation both in cortex and hippocampus might be involved in their selective vulnerability to hypoxia.