The hyperaemic response to passive leg movement is dependent on nitric oxide:a new tool to evaluate endothelial nitric oxide function

Key points Passive leg movement is associated with a ~3-fold increase in blood flow to the leg, but the underlying mechanisms remain unknown. Passive leg movement increased venous levels of metabolites of nitric oxide (NO) in young subjects, whereas they remained unaltered in the muscle interstitial space. Inhibition of NO synthesis lowered the vasodilatory response to passive leg movement by ~90%. The increase in leg blood flow was lower in elderly subjects compared to young subjects and leg blood flow did not increase when passive leg movement was performed by elderly with peripheral artery disease. The results suggest that the hyperaemia induced by passive leg movement is NO dependent. The hyperaemic response to passive leg movement and to ACh was also assessed in elderly subjects and patients with peripheral artery disease.