Exercise type and muscle fiber specific induction of caveolin-1 expression for insulin sensitivity of skeletal muscle.
It is well known that exercise can have beneficial effects on insulin resistance by activation of glucose transporter. Following up our previous report that caveolin-1 plays an important role in glucose uptake in L6 skeletal muscle cells, we examined whether exercise alters the expression of caveolin-1, and whether exercise-caused changes are muscle fiber and exercise type specific. Fifty week-old Sprague Dawley (SD) rats were trained to climb a ladder and treadmill for 8 weeks and their soleus muscles (SOL) and extensor digitorum longus muscles (EDL) were removed after the last bout of exercise and compared with those from non-exercised animals. We found that the expression of insulin related proteins and caveolins did not change in SOL muscles after exercise. However, in EDL muscles, the expression of insulin receptor beta (IR beta) and glucose transporter-4 (GLUT-4) as well as phosphorylation of AKT and AMPK increased with resistance exercise but not with aerobic exercise. Also, caveolin-1 and caveolin-3 increased along with insulin related proteins only in EDL muscles by resistance exercise. These results suggest that upregulation of caveolin-1 in the skeletal muscle is fiber specific and exercise type specific, implicating the requirement of the specific mode of exercise to improve insulin sensitivity.
Oh
Yoon Sin
YS
Department of Biochemistry and Molecular Biology, The Aging and Apoptosis Research Center, Seoul National University College of Medicine, Seoul 110-799, Korea.
Kim
Hyo Jeong
HJ
Ryu
Sung Jin
SJ
Cho
Kyung A
KA
Park
Young Sik
YS
Park
Hyon
H
Kim
MiJung
M
Kim
Chang Keun
CK
Park
Sang Chul
SC
D055372:AMP-Activated Protein Kinases; D000818:Animals; D051242:Caveolin 1 / Q000096:biosynthesis*; D051244:Caveolin 3 / Q000378:metabolism; D005260:Female; D051275:Glucose Transporter Type 4 / Q000096:biosynthesis; D007328:Insulin / Q000502:physiology*; D009097:Multienzyme Complexes / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D010805:Physical Conditioning, Animal; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011972:Receptor, Insulin / Q000096:biosynthesis; D015854:Up-Regulation
D051242:Caveolin 1; D051244:Caveolin 3; D051275:Glucose Transporter Type 4; D007328:Insulin; D009097:Multienzyme Complexes; C495694:Slc2a4 protein, rat; D011972:Receptor, Insulin; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D055372:AMP-Activated Protein Kinases