Effects of exercise on JNK phosphorylation and expression in skeletal muscle of rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of exercise on JNK phosphorylation, protein and gene expression.</p><p><b>METHODS</b>Male rats were randomly divided into control and trained groups. The trained rats were submitted to 1 h or 1.5 h of exercise daily and had a fragment of their excised gastrocenemius muscle, 24 h or 48 h after the last training session. The train lasted for 7 weeks. The changes in the expressions of JNK and p-JNK were determined by Western blotting. The expression of JNK mRNA was determined by RT-PCR.</p><p><b>RESULTS</b>Glucose tolerance test found that blood insulin concentration was decreased with exercise training. Exercise led to a marked increase in p-JNK of trained groups 24 hours after exercise in rats that exercised for 1 hour per day and 24 and 48 hours after the exercise in those that exercised for 1.5 hours per day as compared with controls, and the protein expression of JNK significantly increased 24 and 48 hours after the exercise in rats that exercised for 1.5 hours per day. JNK mRNA was increased by exercise 1.5 h/d, 24 h after the last training session.</p><p><b>CONCLUSION</b>Exercise could increase muscle responsiveness to insulin, improving the total JNK and p-JNK and mRNA expression.</p>

Effects of endurance exercise on ERK1/2 phosphorylation and expression in skeletal muscle of rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of exercise on phosphorylated and total ERK1/2, and mRNA of ERK2.</p><p><b>METHODS</b>Male rats were randomly divided into control and trained groups. The trained rats were submitted to 1 h or 1.5 h of exercise daily and had a fragment of their excised gastroenemius muscle, 24 h or 48 h after the last training session. The train lasted for 7 weeks. The changes in the expressions of ERK1/2 and p-ERK1/2 were determined by Western blotting.The expression of ERK2 mRNA was determined by RT-PCR.</p><p><b>RESULTS</b>Exercise led to a marked increase in p-ERK1/2 of trained groups as compared with controls, and increased ERK1/2 protein expression of training 1.5 h/d, 24 h and 48 h after the last training session. ERK2 mRNA was increased by exercise 1 h/d, 24 h and exercise 1.5 h/d, 24 h and 48 h after the last training session. Glucose tolerance test found that blood insulin concentration was decreased with exercise training.</p><p><b>CONCLUSION</b>Endurance exercise could increase muscle responsiveness to insulin by improving the total ERK1/2 and p-ERK1/2, ERK2 mRNA expression.</p>