运动对老年小鼠心肌bcl-2、bax基因mRNA表达的影响

The Effects of Exercise on the Myocardial Bcl-2 and Bax mRNA Expression in the Aged Mice

探讨运动对心肌bcl-2、bax基因表达的影响及运动与心肌衰老的关系。方法:选取40只12月龄清洁级雄性KM小鼠,随机分成10、20、40分钟运动组和老年对照组,每组10只,运动组实施12周不同的运动方案,应用RT-PCR技术分别对心肌bax和bcl-2基因表达进行测定。结果:RT-PCR检测结果显示:与老年对照组相比,10分钟运动组心肌bax基因mRNA阳性表达(率)降低而bcl-2/bax比值升高(P<0.05);20分钟运动组心肌bcl-2基因mRNA阳性表达(率)和bcl-2/bax比值均显著升高(P<0.01),40分钟运动组的这些指标与老年对照组无显著性差异。结论:(1)运动对心肌bax、bcl-2基因表达的影响与负荷有关,适宜的运动可以抑制心肌bax的表达,促进心肌bcl-2基因表达,使心肌bcl-2/bax比值升高。(2)适宜的运动使心肌细胞bcl-2基因表达增强及bcl-2/bax比值优化,有利于抑制心肌细胞凋亡,促进心肌细胞存活,延缓心肌衰老。

Objective The effects of exercise on the myocardial bcl-2 and bax mRNA expression and the relation to myocardial aging were researched. Methods 40 male KM mice of 12 months were randomly divided into 4 groups： the aged control, 10 minute exercise, 20 minute exercise, 40 minute exercise, and 10 mice per each group. Each exercise group was carried out the exercise plan for total 12 weeks respectively. The myocardial bcl-2 and bax mRNA expression were measured by reverse transcriptional polymerase chain reaction （ RT- PCR）. Results （ 1 ） RT- PCR： Compared with the aged control, the positive expression ratios of bax gene in the heart were decrease in the 10 minute exercise group, but the positive expression ratios of bcl-2 gene in the heart were increase in 20 minute exercise group. The bcl-2/bax ratio in the heart were a significant increase in 10 minute exercise group and 20 minute exercise group（p〈0. 01）. These data were no significant difference both in the aged control and in 40 minute exercise group. Conclusions （1） Effects of exercise on the expression of both bax and bcl-2 genes in heart related to the exercise load, and the suitable load exercise can inhibit bax expression, improve bcl-2 expression and increase bcl-2/ bax ratio. （2） The suitable load exercise can improve bcl-2 expression and increase bcl-2/bax ra tio. It is beneficial to inhibiting apoptosis of myocardium, to advancing myocardium survive and to retarding its aging.