Se和VE对大鼠心肌肌球蛋白重链基因表达影响的研究

从克山病病区粮和非病区粮及病区粮补加Ｓｅ和ＶＥ喂养的大鼠心肌中提取总ＲＮＡ，采用斑点印迹法分析其中的α和β－心肌肌球蛋白重链（ＣＭＨＣ）ｍＲ－ＮＡ含量的变化，并对大鼠血清及心肌组织中的Ｔ４、Ｔ３含量及Ｔ４５－脱单碘酶活性进行了观测。结果表明，与对照组相比，病区粮喂养大鼠心肌组织中的α－ＣＭＨＣｍＲＮＡ含量降低而β－ＣＭＨＣｍＲＮＡ含量升高，同时心肌和血清中Ｔ３含量显著下降，血清Ｔ４增高而心肌Ｔ４变化不大，心肌中Ｔ４５－脱单碘酶活性降低。补加Ｓｅ和ＶＥ后上述改变明显回转，提示克山病致病因素可导致大鼠ＣＭＨＣ基因表达的偏移。Ｓｅ和ＶＥ对心肌肌球蛋白的保护作用可能与心肌Ｔ４５－脱单碘酶活性、Ｔ３含量及其对ＣＭＨＣ基因表达的调控有关。

EFFECTS OF SELENIUM AND VITAMN E ON EXPRESSION OF CARDIAC MYOSIN HEAVY CHAIN GENE IN RATS

Total RNA was extracted from myocardium in rats fed with Keshan disease area grains (endemic grains, EG)and in those fed with EG+Se(0.1μg/g);EG+VE(100μg/g);EG+Se(0.1μg/g)+VE(100μg/g);Non EG as well as stock diet. The cDNA of α and β Cardiac Myosin Heavy Chain (CMHC) labeled with biotin was used as gene probes to detect α and β CMHC mRNA content in rat myocardium by using the dot blot. The results showed that two months after treatment, α CMHC mRNA level was significantly lower and β CMHC mRNA level was significantly higher in myocardium of EG group as compared with those of Non EG group (P<0.05). The concentrations of T 3 in serum and myocardium and T 4 5 monodeiodinase in myocardium of EG group were decreased, but the concentration of T 4 in serum was increased, in addition, a reversible alteration was found after adding Se or/and VE. The results indicate that some pathogenic factors of Keshan disease may alter the expression of the CMHC gene, whereas the Se and VE may have a reversible effect on this change caused by the pathogenic factors. The protective effect of Se and VE on cardiac myosin my be related to T 4 5 monodeiodinase, T 3 concentration in myocardium and expression of the CMHC gene.