Lower capillary density but no difference in VEGF expression in obese vs.lean young skeletal muscle in humans

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Kevin Zwetsloot Ph.D, Associate Professor (Creator)
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/

Abstract: Obesity is associated with lower skeletal muscle capillarization and lower insulin sensitivity. Vascular endothelial growth factor (VEGF) is important for the maintenance of the skeletal muscle capillaries. To investigate whether VEGF and VEGF receptor [kinase insert domain- containing receptor (KDR) and Flt-1] expression are lower with obesity, vastus lateralis muscle biopsies were obtained from eight obese and eight lean young sedentary men before and 2 h after a 1-h submaximal aerobic exercise bout for the measurement of VEGF, KDR, Flt-1, and skeletal muscle fiber and capillary characteristics. There were no differences in VEGF or VEGF receptor mRNA at rest between lean and obese muscle. Exercise increased VEGF (10-fold), KDR (3-fold), and Flt-1 (5-fold) mRNA independent of group. There were no differences in VEGF, KDR, or Flt-1 protein between groups. Compared with lean skeletal muscle, the number of capillary contacts per fiber was the same, but lower capillary density (CD), greater muscle cross sectional area, and lower capillary-to-fiber area ratio were observed in both type I and II fibers in obese muscle. Multiple linear regression revealed that 49% of the variance in insulin sensi- tivity (homeostasis model assessment) could be explained by percent- age of body fat (35%) and maximal oxygen uptake per kilogram of fat-free mass (14%). Linear regression revealed significant relation- ships between maximal oxygen uptake and both CD and capillary-to- fiber perimeter exchange. Although differences may exist in CD and capillary-to-fiber area ratio between lean and obese skeletal muscle, the present results provide evidence that VEGF and VEGF receptor expression are not different between lean and obese muscle.

Additional Information

Timothy P. Gavin, Howard W. Stallings, Kevin A. Zwetsloot, Lenna M. Westerkamp, Nicholas A. Ryan, Rebecca A. Moore, Walter E. Pofahl and Robert C. Hickner (2004) "Lower capillary density but no difference in VEGF expression in obese vs.lean young skeletal muscle in humans" Journal of Applied Physiology #98 pp.315-321 Version of Record Available @ (doi:10.1152/japplphysiol.00353.2004.)
Language: English
Date: 2006
kinase insert domain-containing receptor, Flt-1, exercise, homeostasis model assessment, maximal oxygen uptake, vascular endothelial growth factor

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