High-fat diet impairs the effects of a single bout of endurance exercise on glucose transport and insulin sensitivity in rat skeletal muscle.
A single bout of exercise increases the rate of muscle glucose transport (GT) by both insulin-independent and insulin-dependent mechanisms. The purpose of this study was to determine whether high-fat diet (HFD) feeding interferes with the metabolic activation induced by moderate-intensity endurance exercise. Rats were fed an HFD or control diet (CD) for 4 weeks and then exercised on a treadmill for 1 hour (19 m/min, 15% incline). Insulin-independent GT was markedly higher in soleus muscle dissected immediately after exercise than in muscle dissected from sedentary rats in both dietary groups, but insulin-independent GT was 25% lower in HFD-fed than in CD-fed rats. Insulin-dependent GT in the presence of submaximally effective concentration of insulin (0.9 nmol/L) was also higher in both dietary groups in muscle dissected 2 hours after exercise, but was 25% lower in HFD-fed than in CD-fed rats. Exercise-induced activation of 5'adenosine monophosphate-activated protein kinase, a signaling intermediary leading to insulin-independent GT and regulating insulin sensitivity, was correspondingly blunted in the HFD group. High-fat diet did not affect glucose transporter 4 content or insulin-stimulated Akt phosphorylation. Our findings provide evidence that an HFD impairs the effects of short-term endurance exercise on glucose metabolism and that exercise does not fully compensate for HFD-induced insulin resistance in skeletal muscle. Although the underlying mechanism is unclear, reduced 5'adenosine monophosphate-activated protein kinase activation during exercise may play a role.
Tanaka
Satsuki
S
Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Hayashi
Tatsuya
T
Toyoda
Taro
T
Hamada
Taku
T
Shimizu
Yohei
Y
Hirata
Masakazu
M
Ebihara
Ken
K
Masuzaki
Hiroaki
H
Hosoda
Kiminori
K
Fushiki
Tohru
T
Nakao
Kazuwa
K
D000263:Adenylate Kinase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D004789:Enzyme Activation; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000201:enzymology / Q000378:metabolism / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D051058:Oncogene Protein v-akt / Q000378:metabolism; D010766:Phosphorylation; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000378:metabolism
D004041:Dietary Fats; D051275:Glucose Transporter Type 4; C495694:Slc2a4 protein, rat; D014280:Triglycerides; D006003:Glycogen; D051058:Oncogene Protein v-akt; D000263:Adenylate Kinase; D005947:Glucose