预处理延迟相对金属硫蛋白及缺血再灌注损伤心肌细胞凋亡的影响

The Effects of the Lag Phase of Preconditioning on Metallothionein, and Cadiocyte Apoptosis Caused by Ischemia/Reperfusion

目的:探讨缺血预处理(IPC)延迟相对大鼠心肌金属硫蛋白(MT)含量以及大鼠缺血再灌注(I/R)损伤心肌细胞凋亡、Bcl-2和丙二醛(MDA)的影响。方法:采用Western blot蛋白印迹、缺口末端标记法(TUNEL)、免疫组织化学方法和生物化学方法。结果:(1)IPC组Western blot蛋白印迹MT含量显著增加,免疫组织化学得到同样的结果(P<0.05);MDA含量显著减少,与MT表达量呈负相关性(P<0.05);TUNEL法阳性心肌细胞核数以及凋亡阳性率均明显少于对照组,且与MT的表达量呈负相关(P<0.05);(2)IPC组表达Bcl-2蛋白阳性心肌细胞数以及阳性率均高于对照组(P<0.05),但与MT的表达量无显著相关性。结论:(1)MT可能参与了IPC延迟相的保护作用;(2)Bcl-2也参与了IPC延迟相保护作用,但与MT表达量的增加可能无直接关系。

Objective： To investigate whether metallothionein （MT） involves in the delayed protection of cardocytes in 24 hours after ischemia preconditioning （IPC）, and the relationship between MT and the second window of IPC. Methods： Western blot, TUNEL, immunohistochemistry methods, and biochemistry techniques were used in this research. Results： （1） Western blot analysis with anti- MT antibodies demonstrated a marked increase in IPC group and the similar results came from the immunohistochemistry analysis; The MDA contents reduced in IPC group significantly and showed a negative correlation with MT contents. TUNEL analysis results showed that the numbers of cardiocyte nuclus and the apoptosis percentage of cardiocytes in IPC group were significantly lower than those of control group （ P 〈 0. 05 ）, and negatively correlated with MT contents. （ 2 ） The numbers of cardiocytes with protein Bcl-2 positive expression and the protein Bcl-2 positive rates in IPC group were markedly higher than those in control group. No correlation was found between the Bcl-2 positive cardiocyte numbers and the MT contents. Conclusion： MT might be involved in protective effects of IPC in the second window of preconditioning. Bcl-2 might be involved too, but not relate with the increase of MT content directly.