[A non-invasive method for detecting endothelium-dependent dilation].

Using high resolution ultrasound, we measured the diameter of brachial arteries at rest, during reactive hyperemia and after glyceryl trinitrate (GTN) taking in 22 healthy persons. The results showed that brachial artery dilation was present both in reactive hyperemia and response to GTN. The mean flow-mediated dilation was 13.8 +/- 3.9% increment. The mean increment of dilation in response to GTN was 24.9 +/- 9.7%. The diameters of brachial arteries during reactive hyperemia and after sublingual GTN had significant difference compared with that in baseline (P < 0.01). It indicates that increased flow may mediate endothelium-dependent vessel dilatation and GTN cause endothelium-independent vessel dilatation in normal subjects. This paper presents a new non-invasive method of detecting endothelium-dependent dilation, which is proved to be simple, secure and practical.