运动对大鼠肌细胞丝裂素活化蛋白酶信号传导系统的调节作用

Effects of exercise on mitogen-activated protein kinase signaling pathways in myocardial and skeletal muscles of rats

目的 观察运动对心肌和骨骼肌细胞应激激活蛋白激酶 (JNK)信号通道活性的影响 ,为运动处方的制定提供分子生物学依据。方法 1 2周龄、体重 2 0 0～ 2 30克的SD大鼠 1 8只 ,随机分为对照组 (n =6)、急性运动组 (n=6)和运动训练组 (n =6)。采用活动平板 ,坡度 1 0 % ,速度 2 0m/min,运动时间 2 0分 /次。急性运动组仅运动 2 0min ;运动训练组 ,每日 1次 ,每周 5次 ,运动三周 ;对照组不参与运动。运用化学发光测定心肌和骨骼肌JNK活性。结果 骨骼肌JNK活性在急性运动组和运动训练组分别是非运动组的 4 .1倍和1 1 .1倍 ,且运动训练组较急性运动组增高 2 .71倍。心肌JNK活性在急性运动组和运动训练组分别是非运动组的 3 .5倍和 2 .1 6倍 ,且急性运动组较运动训练组增高 1 .62倍。结论 运动可以激活心肌和骨骼肌JNK信号转导通道 。

Objective To expore the effects of both acute exercise and exercise training on JNK signaling pathways in myocardial and skeletal muscles of rats. Methods Eighteen male Sprague Dawley rats weighing 200 230g with 12 weeks of age were randomly divided into the following three groups:acute exercise( n =6),exercise training( n =6) and control( n =6). Rats in the exercise groups were forced to run on a treadmill with 10% grade at speed of 20 m/min. Acute exercise group was submitted to a 20 min bout of running exercise. Exercise training group was forced to treadmill exercise five times a week for three weeks. The rats in the control group did not carry out any treadmill exercise. SAPK/JNK activities in muscles were measured by a nonradioactive method. Results JNK activity in skeletal muscles increased 4.1 times in acute exercise group and 11.1 times in exercise training group comparing to the control group,and the peak value was seen in the exercise training group. JNK activity in cardiac muscles increased to 3.5 times in acute exercise group and 2.16 times in exercise training group comparing to the control group, and the peak value was in the acute exercise group. Conclusion Both the acute exercise and excercise training may activate muscle JNK signal pathway, and the increase of JNK activity both in cardiac and skeletal muscles is influenced in certain degree by either the duration or the frequency of the exercise.