中文摘要：

目的：通过观察重复性低氧刺激对蛋白激酶CβⅠ和βⅡ亚型（cPKCβⅠ，cPKCβⅡ）膜转位水平（或激活程度）的影响，初步探讨cPKCs特定亚型在脑低氧预适应发生发展过程中的作用。方法：按我室已建立的小鼠低氧预适应模型方法，制备重复性低氧1—4次小鼠（H1-H4）。应用SDS-聚丙烯酰胺凝胶蛋白电泳（SDS—PAGE）、蛋白印迹（Western blot）等生化技术，并结合应用Gel Doc凝胶成像系统，半定量检测小鼠海马和大脑皮层组织内cPKCβⅠ和βⅡ的膜转位水平。结果：随低氧刺激次数（H1-H4）的增加，小鼠海马组织内cPKCβⅡ的膜转位水平升高，H4组膜转位水平显著高于H0（100％，12=10）和H1（79．5％±10．7％，12=10）组（173．3％±21．3％，P〈0．01，12=10）；同样，大脑皮层内cPKC βⅡ膜转位水平也随低氧次数的增加而升高，H3（119．8％±7．7％，12=6）和H4（131．8％±4．7％，12=6）组膜转位水平均显著高于H0（100％，n=6）组（P〈0．05，n=6）；而cPKCβⅠ亚型的膜转位水平无论在大脑皮层还是海马组织内的变化均不显著（P〉0．05，12=8）。结论：cPKCβⅡ膜转位（激活）可能在脑低氧预适应的发生发展过程中发挥着重要作用。

英文摘要：

AIM： To explore the role of cPKCs in the development of cerebral hypoxic preconditioning, the effect of repetitive hypoxia on the level of protein kinases C βⅠand βⅡ （cPKC βⅠand βⅡ） membrane translocation in the brain of mice was observed. METHODS： The hypoxic preconditioned mouse model was adapted with minor modification from our previous report. The biochemistry techniques of SDS - PAGE and Western blotting were applied to determine the level of cPKC βⅠand βⅡ membrane translocation in cortex and hippocampus of mice. RESULTS： cPKC βⅡ translocated from the cytosolic fraction to the particulate fraction in response to the repetitive hypoxic exposure （H1 - H4） both in hippocampus and cortex of mice, which was regarded as membrane translocation. The significant membrane translocation of cPKC βⅡ was found in hippocmnpus of H4 group （173.3% ± 21.3% vs H0： 100% or HI： 79.5% ±10.7%, P〈0.01, n = 10） and in cortex of H3 （119.8% ±7.7%） and H4 （131.8% ± 4.7% ） groups （ vs H0： 100%, P 〈 0.05, n = 6） respectively. However, there were no significant changes of cPKC βⅠ membrane translocation in cortex and hippocampus of hypoxic preconditioned mice （ P 〉 0.05, n = 8）. CONCLUSION： These results suggest that cPKC βⅡ may play an important role in the development of cerebral hypoxic preconditioning, but the changes of novel and typical PKC isoenzymes are still under investigation.