St-Pierre, P and Keith, LJ and Richards, SM and Rattigan, S and Keske, MA, Microvascular blood flow responses to muscle contraction are not altered by high-fat feeding in rats, Diabetes, Obesity and Metabolism, 14, (8) pp. 753-761. ISSN 1462-8902 (2012) [Refereed Article]
Copyright 2012 Blackwell Publishing Ltd.
Aim: Exercise and insulin each increase microvascular blood flow and enhance glucose disposal in skeletal muscle. We have reported that insulin-mediated microvascular recruitment in a diet-induced model of insulin resistance (high-fat feeding for 4 weeks) is markedly impaired; however, the effect of muscle contraction in this model has not been previously explored.
Methods: We fed rats either normal (ND, 10% calories from fat) or high-fat (HFD, 60% calories from fat) diets ad libitum for 4–8 weeks. Animals were then anaesthetized and one hindlimb electrically stimulated to contract at 0.05, 0.1 and 2 Hz (field stimulation, 30 V, 0.1 ms duration) in 15 min stepwise increments. Femoral artery blood flow (Transonic flow probe), muscle microvascular blood flow (hindleg metabolism of 1-methylxanthine and contrast-enhanced ultrasound) and muscle glucose disposal (uptake of radiolabelled 2-deoxy-d-glucose and hindleg glucose disappearance) were measured.
Results: Both ND and HFD rats received the same voltage across the leg and consequently developed the same muscle tension. Femoral artery blood flow in the contracting leg increased during 2 Hz contraction, but not during the lower frequencies and these effects were similar between ND and HFD rats. Muscle microvascular blood flow significantly increased in a contraction frequency-dependent manner, and preceded increases in total limb blood flow and these effects were similar between ND and HFD rats. Muscle glucose disposal was markedly elevated during 2 Hz contraction and was comparable between ND and HFD rats.
Conclusion: Contraction-mediated muscle microvascular recruitment and glucose uptake are not impaired in the HFD insulin resistant rat.
|Item Type:||Refereed Article|
|Keywords:||dietary fat, insulin resistance, microvascular perfusion, muscle glucose uptake|
|Research Division:||Medical and Health Sciences|
|Research Group:||Medical Physiology|
|Research Field:||Systems Physiology|
|Objective Group:||Clinical Health (Organs, Diseases and Abnormal Conditions)|
|Objective Field:||Cardiovascular System and Diseases|
|UTAS Author:||St-Pierre, P (Mr Philippe St Pierre)|
|UTAS Author:||Keith, LJ (Miss Laura Keith)|
|UTAS Author:||Richards, SM (Dr Stephen Richards)|
|UTAS Author:||Rattigan, S (Professor Stephen Rattigan)|
|UTAS Author:||Keske, MA (Dr Michelle Keske)|
|Funding Support:||Australian Research Council (DP0877385)|
|Web of Science® Times Cited:||9|
|Deposited By:||Menzies Institute for Medical Research|
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