Influence of prior anterograde shear rate exposure on exercise‐induced brachial artery dilation. Issue 5 (25th May 2015)

• Record Type: Journal Article
• Authors: Ade, Carl J.; Brown, Michael G.; Ederer, Austin K.; Hardy, Rachel N.; Reiter, Landon K.; Didier, Kaylin D.
• Is Part Of: Physiological reports. Volume 3:Issue 5(2015:May)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-05-25
• Subjects: Blood Flow -- exercise -- shear rate; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.12414
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Shear rate can elicit substantial adaptations to vascular endothelial function. Recent studies indicate that prior exposure to anterograde flow and shear increases endothelium‐dependent flow‐mediated dilation at rest and that anterograde shear can create an anti‐atherosclerotic and provasodilatory state. The primary aim of the present study was therefore to determine the effects of prior exposure to anterograde shear on exercise‐induced brachial artery dilation, total forearm blood flow (FBF), and vascular conductance (FVC) during dynamic handgrip exercise. Eight men completed a constant‐load exercise test corresponding to 10% maximal voluntary contraction, prior to (baseline) and following a 40 min shear rate intervention (post‐SRI) achieved via unilateral forearm heating, which has previously been shown to increase anterograde shear rate in the brachial artery. During the SRI, anterograde shear rate increased 60.9 ± 29.2 sec −1 above baseline ( P < 0.05). Post‐SRI, the exercise‐induced brachial artery vasodilation was significantly increased compared to baseline (4.1 ± 0.7 vs. 4.3 ± 0.6 mm, P < 0.05). Post‐SRI FBF mean response time (33.2 ± 16.0 vs. 23.0 ± 11.8 sec, P < 0.05) and FVC mean response time (31.1 ± 12.8 20.2 ± 10.7 sec, P < 0.05) at exercise onset were accelerated compared to baseline. These findings demonstrate that prior exposure to anterograde shear rate increases the vascular responses to exercise and supports the possible beneficial effects of anterograde shear rate in vivo. Abstract : The primary aim of the present study was to determine the effects of prior exposure to anterograde shear on exercise‐induced brachial artery dilation, total forearm blood flow and vascular conductance during dynamic handgrip exercise. Prior anterograde shear rate significantly increased the rate of blood flow and vascular conductance during exercise. These results support the hypothesis that prior acute exposure to anterograde shear increases the brachial artery vasodilator response to moderate intensity exercise; which supports previous evidence that shear rate can significantly alter vascular function.