The following techniques will be used:
Endothelial function will be measured non-invasively by flow-mediated changes in pulsatile blood volume in the finger-tips.
Vascular compliance (stiffness) will be assessed by tonometry of the radial pulse wave ("augmentation index") and diastolic puse wave analysis.
Plasma nitrate/nitrite levels mirror NO production and will be measured spectrophotometrically by the Griess reaction.
Plasma nitrotyrosine, an in vivo marker of NO-dependent damage induced by reactive nitrogen intermediates derived from NO, will be measured by ELISA.
Exhaled NO may provide an real-time measure of endothelial cell NO production and can be measured by a hand-held device which contains an electrochemical detector sensitive to 5 ppb.