Effect of Resistance Training on Microvascular Density and eNOS Content in Skeletal Muscle of Sedentary Men. (November 2014)

• Record Type: Journal Article
• Authors: Cocks, Matthew; Shaw, Christopher S.; Shepherd, Sam O.; Fisher, James P.; Ranasinghe, Aaron M.; Barker, Thomas A.; Tipton, Kevin D.; Wagenmakers, Anton J. M.
• Is Part Of: Microcirculation. Volume 21:Number 8(2014:Nov.)
• Page Start: 738
• Page End: 746
• Publication Date: 2014-11
• Subjects: Biological transport -- Periodicals; Microcirculation -- Physiology -- Periodicals; 612.135
• DOI: 10.1111/micc.12155
• Languages: English
• ISSNs: 1073-9688

Abstract

<abstract abstract-type="main" id="micc12155-abs-0001"> <title>Abstract</title> <sec id="micc12155-sec-0001" sec-type="section"> <title>Objective</title> <p>The effects of RT on muscle mass, strength, and insulin sensitivity are well established, but the underlying mechanisms are only partially understood. The main aim of this study was to investigate whether RT induces changes in endothelial enzymes of the muscle microvasculature, which would increase NO bioavailability and could contribute to improved insulin sensitivity.</p> </sec> <sec id="micc12155-sec-0002" sec-type="section"> <title>Methods</title> <p>Eight previously sedentary males (age 20 ± 0.4 years, BMI 24.5 ± 0.9 kg/m<sup>2</sup>) completed six weeks of RT 3x/week. Muscle biopsies were taken from the m. vastus lateralis and microvascular density; and endothelial‐specific eNOS content, eNOS Ser<sup>1177</sup> phosphorylation, and NOX2 content were assessed pre‐ and post‐RT using quantitative immunofluorescence microscopy. Whole‐body insulin sensitivity (measured as Matsuda Index), microvascular <italic>K</italic><sub>f</sub> (functional measure of the total available endothelial surface area), and arterial stiffness (AIx, central, and pPWV) were also measured.</p> </sec> <sec id="micc12155-sec-0003" sec-type="section"> <title>Results</title> <p>Measures of microvascular density, microvascular <italic>K</italic><sub>f</sub>, microvascular eNOS content, basal eNOS phosphorylation, and endothelial NOX2 content did not change from pre‐RT to post‐RT. RT increased insulin sensitivity (<italic>p </italic>< 0.05) and reduced resting blood pressure and AIx (<italic>p </italic>< 0.05), but did not change central or pPWV.</p> </sec> <sec id="micc12155-sec-0004" sec-type="section"> <title>Conclusions</title> <p>RT did not change any measure of muscle microvascular structure or function.</p> </sec> </abstract>