Effect of swimming exercise on MEK and ERK1 phosphorylation level in adipose tissue of insulin resistance rats

OBJECTIVE: To investigate the effect of chronic and acute swimming exercise intervention on the mitogen-activated extracellular signal-regulated kinase(MEK) and extracellular signal-regulated kinase 1(ERK1) phosphorylation level in adipose tissues of obesityinduced insulin resistance rats. METHODS: A total of 100 SD rats were randomly divided into control group(n=10) fed with normal diet and high-fat diet group(n=90) fed with high fat diet. After 8 weeks, one third rats(n=30) with upper weight in high-fat diet group were selected and randomly divided into high-fat diet sedentary group(n=10), chronic exercise group(n=10) and acute exercise group(n=10). Under another 8-week high-fat diet feeding, exercise intervention was performed according to the exercise procedure; control group was fed with normal diet for 8 weeks. After exercise intervention, visceral adipose tissues were separated and MEK and ERK1 phosphorylation level in adipose tissue was detected by Western blot method. RESULTS: Chronic exercise intervention significantly reduced body weight, visceral fat weight and visceral fat weight/body weight ratio(P<0. 01), and acute exercise intervention had no significant effect on body weight, visceral fat weight and visceral fat weight/body weight ratio. Both chronic and acute exercise intervention significantly increased body insulin sensitivity(P<0. 05), as well as significantly decreased MEK and ERK1 phosphorylation level in adipose tissues(P<0. 01). CONCLUSION: The improvement of obesity-induced insulin resistance by exercise might be related to inhibited phosphorylation of MEK and ERK1 in adipose tissues.