BACKGROUND: Both altered shear rate and @entity2232 ( @entity2232 ) are associated with the age-related development of @entity731 . However, the role of @entity2232 , a potent endogenous vasoconstrictor, in altering shear rate in @entity1 , especially in the atherosclerotic-prone vasculature of the leg, is unknown. Therefore, this study examined the contribution of @entity2232 to the age-related alterations in common femoral artery ( @entity3795 ) shear rate. METHOD: @entity11344 , a specific endothelin type A (ET(A)) receptor antagonist, was infused into the @entity3795 , and diameter and blood velocity were measured by Doppler ultrasound in young (n=8, 24  2 years) and old (n=9, 70  2 years) study @entity1 . RESULTS AND CONCLUSION: The old had greater intima-media thickening in the @entity3795 , indicative of a preatherogenic phenotype. Prior to infusion, the old study @entity1 exhibited reduced mean shear rate (27  3/s) compared with the young study @entity1 (62  9/s). This difference was likely driven by attenuated antegrade shear rate in the old as retrograde shear rate was similar in the young and old. Inhibition of ETA receptors, by @entity11344 , increased leg blood flow in the old, but not in the young, abolishing age-related differences. Older study @entity1 had a larger @entity3795 (young: 0.82  0.03cm, old: 0.99  0.03cm) in which @entity11344 induced significant vasodilation (5.1  1.0%), but had no such effect in the young (-0.8  0.8%). Interestingly, despite the age-specific, @entity11344 -induced increase in leg blood flow and @entity3795 diameter, shear rate patterns remained largely unchanged. Therefore, @entity2232 , acting through the ETA receptors, exerts a powerful age-specific vasoconstriction. However, removal of this vasoconstrictor stimulus does not augment mean shear rate in the old.

Endogenous XXXX and femoral artery shear rate: impact of age and implications for @entity731 .

@entity1 :: ('9606', 'Species') :: ['participants', 'humans'] @entity2232 :: ('1906', 'Gene') :: ['endothelin-1', 'ET-1'] @entity3795 :: ('31658', 'Species') :: ['CFA'] @entity11344 :: ('MESH:C072247', 'Chemical') :: ['BQ-123'] @entity731 :: ('MESH:D050197', 'Disease') :: ['atherosclerosis']
@entity2232 :: (1906,Gene) :: ['endothelin-1']
