트레드밀 강도별 운동이 흰쥐 가자미근의 GLUT-4 mRNA와 갈색지방조직의 GLUT-2 mRNA 발현에 미치는 영향

Abstract

In the present study, the effect of different exercise intensities training on the blood glucose tolerance, GLUT-4 mRNA of soleus muscle and GLUT-2 mRNA expression of brown adipose tissue in rats was investigated. The F344 rats were classified into four groups, 10 rats each: the control group(Con), the low intensity exercise group(low), the moderate intensity exercise group(moderate) and the high intensity exercise group(high). Rats of the exercise groups were made to run on a motorized treadmill by different intensity to each group for 30minutes once a day during 12 weeks. Blood glucose in rat`s tail was measured by Super Glucocard II. GLUT-4 mRNA of soleus muscle and GLUT-2 mRNA expression of brown adipose tissue in rats were also measured by RT-PCR and western blotting. It was shown that glucose tolerance was significantly increased following the low and moderate exercise group after 12 weeks. Also, GLUT-4 mRNA of soleus muscle was significantly increased following the low and the moderate exercise training compared to the high exercise group after 12 weeks. Furthermore, GLUT-2 mRNA of brown adipose tissue was significantly increased following the moderate exercise training compared to the low and the high exercise group after 12 weeks. It is concluded that low and moderate intensity exercise induces translocation of GLUT-4 mRNA and GLUT-2 mRNA which result in increased blood inflow thus glucose tolerance is increased. Increased GLUT-4 mRNA expression may be mediated by the enzyme AMP-activated kinase, which is activated during exercise and has been demonstrated to increase GLUT-4 transcription. Further research needs to be done to investigate whether AMP-activated kinase activates myocyte enhancer factor-2 and GLUT-4 enhancer factor to increase transcription of the GLUT-4 gene.