TY - JOUR
T1 - Role of retrograde flow in the shear stimulus associated with exercise blood flow
AU - Gonzales, Joaquin
AU - Thompson, Benjamin C.
AU - Thistlethwaite, John R.
AU - Scheuermann, Barry W.
PY - 2008/5/12
Y1 - 2008/5/12
N2 - To test the hypothesis that retrograde flow influences the shear stimulus of exercise blood flow, eight healthy men [25.6+/-3.1 years (SD)] performed 20 min of single-leg knee-extension exercise at two contraction velocities: fast (FR, 1.5 m s(-1)) and slow (SR, 0.4 m s(-1)). Contraction frequency (30 cpm) and workload (5 kg) were kept constant resulting in a work rate of 15.25 W for both contraction velocities. Common femoral artery diameter and blood velocity were measured at rest and during exercise using ultrasound Doppler. Mean blood flow was not different between contraction velocities while antegrade (2012.4+/-379.9 versus 1745.6+/-601.5 ml min(-1); P=0.05) and retrograde (121.7+/-43.0 versus 11.2+/-6.6 ml min(-1); P<0.001) flows were higher during FR than SR contractions, respectively. Despite the similar mean blood flow response, vascular resistance was lower during FR than SR contractions (0.06+/-0.01 versus 0.08+/-0.03 units; P=0.03) and was closely related to shear rate (p
AB - To test the hypothesis that retrograde flow influences the shear stimulus of exercise blood flow, eight healthy men [25.6+/-3.1 years (SD)] performed 20 min of single-leg knee-extension exercise at two contraction velocities: fast (FR, 1.5 m s(-1)) and slow (SR, 0.4 m s(-1)). Contraction frequency (30 cpm) and workload (5 kg) were kept constant resulting in a work rate of 15.25 W for both contraction velocities. Common femoral artery diameter and blood velocity were measured at rest and during exercise using ultrasound Doppler. Mean blood flow was not different between contraction velocities while antegrade (2012.4+/-379.9 versus 1745.6+/-601.5 ml min(-1); P=0.05) and retrograde (121.7+/-43.0 versus 11.2+/-6.6 ml min(-1); P<0.001) flows were higher during FR than SR contractions, respectively. Despite the similar mean blood flow response, vascular resistance was lower during FR than SR contractions (0.06+/-0.01 versus 0.08+/-0.03 units; P=0.03) and was closely related to shear rate (p
U2 - 10.1111/j.1475-097X.2008.00812.x
DO - 10.1111/j.1475-097X.2008.00812.x
M3 - Article
SP - 318
EP - 325
JO - Clinical Physiology and Functional Imaging
JF - Clinical Physiology and Functional Imaging
ER -