Resumen de Blood Flow Restriction Enhances Post-Resistance Exercise Angiogenic Gene Expression.
Kelly A. Larkin, Thomas W. Buford, R. Gavin Macneil, Todd M. Manini, Marvin Dirain, Bhanupresad Sandesara
AB Purpose: The objective of this study is to evaluate the effects of blood flow restriction (BFR) on muscle oxygenation during low-intensity resistance exercise as well as postexercise expression of molecules related to physiological angiogenesis. Methods: Using a randomized cross-over design, six apparently healthy young adults (22 +/- 1 yr) performed 120 unilateral knee extensions at 40% of 1 repetition maximum with and without BFR (CNTRL). Near-infrared spectroscopy was used to measure oxygenation of the vastus lateralis during exercise. Serum and muscle expression of Post-Resistance vascular endothelial growth factor (VEGF) were determined preexercise, 4 h postexercise, and 24 h postexercise. Transcript (mRNA) expression of VEGF and other angiogenic genes was also determined. Results: BFR increased muscle hemoglobin (Hb) concentrations during exercise (14.4 +/- 1.6 vs. 0.9 +/- 1.6, P = 0.002), driven largely by an increase in deoxygenated Hb (11.0 +/- 2.5 vs. 0.5 +/- 1.1, P = 0.030). BFR also increased (P < 0.05) transcript expression of VEGF, VEGF-R2, hypoxia-inducible factor 1 alpha, inducible nitric oxide synthase (NOS), and neuronal NOS. The most dramatic change in response to BFR was an increase in VEGF mRNA at 4 h postexercise (4.1 +/- 0.6 vs. 0.6 +/- 0.2-fold change, P = 0.028). Compared with control, transcript expression of endothelial NOS, serum VEGF, or muscle protein expression of VEGF was not altered in response to BFR (P > 0.05). Conclusion: Acute BFR increases postexercise expression of mRNA related to skeletal muscle angiogenesis, plausibly in response to changes in muscle Hb concentrations. (C)2012The American College of Sports Medicine
