不同强度运动后大鼠心肌细胞热休克蛋白72mRNA的表达

Effects of Different Exercise Intensities on the Expression of Heat Shock Protein 72 mRNA in Myocardium of Rats

目的 :探讨不同运动强度和持续时间运动对大鼠心肌细胞热休克蛋白 72mRNA表达的影响。方法 :分别使SD大鼠进行低强度 (6 0 %VO2 max)、中等强度 (75 %VO2 max)和高强度 (85 %VO2 max)跑台运动 1天、2天和 3天 ,在末次运动结束后 2 4小时以RT -PCR法检测大鼠心肌细胞热休克蛋白 72mRNA的表达。结果 :在安静情况下大鼠心肌细胞存在HSP72mRNA的基础结构性表达 ;低强度运动 1天后心肌细胞HSP72mRNA表达与对照组相比无显著性差异 ,但随着运动时间的延长 ,HSP72mRNA表达逐渐增加 ;中等强度运动后心肌细胞HSP72mRNA表达随运动持续时间的延长显著增加 ,但运动 2天和 3天组表达量无显著性差异 ;大强度运动后心肌细胞HSP72mRNA表达随运动持续时间的延长显著增加。结论 :运动可以造成心肌细胞HSP72mRNA的表达增加 ,不同强度运动诱导心肌细胞HSP 72mRNA表达程度不同 ,且与运动持续时间存在内在关系。

Objective To study whether exercises of different intensities can effectively induce the expression of myocardial HSP72 messenger RNA (mRNA). Methods 60 SD rats were randomly divided into four groups: (1) control group (n = 6), (2) 60% VO_2max group (n = 18), (3) 75% VO_2max group (n = 18), and (4) 85% VO_2max group (n = 18). Each exercise group had 3 groups in which the rats were trained on treadmill for 1 day, 2 days, 3 days,respectively. After training, all rats were decapitated at intervals of 24 hr and HSP 72 mRNA expression of myocardium was detected by reverse transcription-polymerase chain reaction (RT-PCR). Results (1) HSP72 mRNA could be basically expressed in rats in control group. (2)There was not a significant increase of HSP72 mRNA in myocardial cells in 1-day-exercise group at 60% VO_2max compared with control. But with the increasing of exercise duration, the expression of myocardial HSP72 mRNA increased. (3) In 75% VO_2max group, with the increasing of exercise duration, the expression of myocardial HSP72 mRNA increased significantly. But there is not a significance difference between 1-day-exercise and 2-day-exercise group. (4) In 85% VO_2max group, with the increasing of exercise duration, the expression of myocardial HSP72 mRNA increased significantly. Conclusion Exercise is a sufficient stimulus to induce or enhance the synthesis of heat shock and/or stress proteins in myocardial cells. The expression of myocardial HSP72 mRNA varied with different exercise intensities and correlated with durations of the exercise.