CHANGES OF THE EXPRESSION FOR THE STRESS PROTEINS IN RAT SKELETAL MUSCLES

我们在2000-2002年进行了两次实验。一个是再生大鼠比目鱼肌中热休克蛋白的表达，另一个是肥大大鼠比目鱼肌中热休克蛋白的表达。(1)热休克蛋白在再生大鼠比目鱼肌中的表达：注射布比卡因使比目鱼肌纤维变性。在注射后第4天观察到再生纤维，并且在恢复第4周期间纤维面积逐渐增加。再生纤维中HSP 72水平随再生纤维的生长而增加。提示HSP 72与再生纤维的生长有关。(2)HSPs在肥大大鼠比目鱼肌中的表达：饮水给予克伦特罗4周后，比目鱼肌纤维，尤其是快缩肌纤维明显肥大。慢比目鱼肌肌纤维类型组成和肌球蛋白重链组成的配置文件被改变为“快”型与克伦特罗治疗。肌球蛋白重链亚型共表达观察克伦特罗处理比目鱼肌单纤维。而HSP 72在肥大的比目鱼肌中的表达水平明显降低。我们的研究结果清楚地表明，HSP 72在克伦特罗诱导的肥大比目鱼肌中减少，并表明HSP 72与肌肉肥大没有直接关系。

We performed two experiments in 2000-2002. One is the expression of heat shock proteins (HSPs) in regenerating rat soleus muscle, and the other is the expression of HSPs in hypertrophied rat soleus muscle.(1) The expression of HSPs in regenerating rat soleus muscle : the soleus muscle fibers were degenerated by injection of bupivacain. The regenerate fibers were observed at day 4 after the injection, and the fiber area gradually increased during recovery week 4. The HSP72 levels in regenerating fibers increased consistently with the growth for the regenerating fibers. These results may suggest that the HSP72 is related to the growth for the regenerating fibers.(2) The expression of HSPs in hypertrophied rat soleus muscle : soleus muscle fibers, especially the fast-twitch fibers, were hypertrophied by clenbuterol administration in drinking water for 4 weeks. The fiber type composition and the profiles of myosin heavy chain composition were changed toward "Fast" types in the slow soleus muscle treated with clenbuterol. Coexpression of myosin heavy chain isoforms were observed in the clenbuterol-treated soleus single fibers. However, the expression level of HSP72 was dramatically decreased in hypertrophied solesu muscle. Our results clearly indicate that the HSP72 was decreased in hypertrophied soleus muscle induced by clenbuterol, and suggest that the HSP72 is not related directly to the muscle hypertrophy.