Opposing effects of shear-mediated dilation and myogenic constriction on artery diameter in response to handgrip exercise in humans.

摘要: While the impact of changes in blood flow and shear stress on artery function are well documented, acute effects increases arterial pressure less described humans. The aim this study was to assess effect 30 min elevated pressure, absence or sympathetic nervous system (SNS) activation, conduit diameter. Ten healthy male subjects undertook three sessions unilateral handgrip exercise at 5, 10, 15% maximal voluntary contractile (MVC) strength. Brachial rate profiles were measured simultaneously during active contralateral resting arms. Bilateral brachial diameter assessed before immediately postexercise. In a second experiment, six repeated MVC condition while continuous vascular measurements collected muscle nerve activity (MSNA) assessment using peroneal microneurography. We found that strength induced stepwise elevations (P < 0.01, Δmean pressure: 7.06 ± 2.44, 8.50 2.80, 18.35 3.52 mmHg, P 0.01). Whereas evident exercising arm 0.001), no apparent nonexercising limb = 0.42). increased 0.02), but significantly decreased 0.03). At MVC, different between arms (interaction effect: 0.01), whereas level exertion produced significant MSNA. conclude transmural independent SNS reduce caliber normotensive humans vivo. These mitigated by exercise-induced limb.