Endothelial dysfunction is a common pathophysiological feature which develops in the evolution of cardiovascular diseases. Strategies to maintain a healthy endothelium or to reverse endothelial dysfunction are crucial for the normal function of the cardiovascular system and the maintenance of cardiovascular health. Endothelial dysfunction is observed both in the coronary and peripheral vasculature. Studies have demonstrated that surgical preparation of coronary artery bypass grafts can cause endothelial dysfunction and influence the viability and patency of these grafts. An important consideration in the improvement of surgical techniques is to prevent damage to the endothelium during harvesting and implantation. The relative influence of the Mayo stripper minimally invasive long saphenous vein (LSV) harvesting technique and the influence of internal mammary artery (IMA) pedicle width in preserving the integrity of endothelial function are uncertain. Increased production of reactive oxygen species, in particular, superoxide and radicals derived from superoxide, has been associated with endothelial dysfunction in animal models of disease, and there is increasing evidence of a link between oxidative stress and endothelial dysfunction in humans. It has been reported that endothelial dysfunction and increased oxidative stress may predict future events in patients with coronary artery disease. However, concurrent and comparative data on endothelial function, direct measures of superoxide in human vessels, and biomarkers of oxidative stress are not available simultaneously in patients with coronary artery disease nor in control subjects with no documented cardiovascular disease. Circulating biomarkers of oxidative stress have been investigated in patients with essential hypertension and in control subjects, but the relationship between these markers and endothelial function has not been examined. In addition, although the degree of endothelial function has been consistently linked to the number of risk factors present in patients with coronary artery disease, the relative importance of individual risk factors in determining levels of oxidative stress and endothelial function remains uncertain. To address these questions, this thesis studied the influence of harvesting techniques and cardiovascular risk factors on endothelial function of human blood vessels commonly used in coronary artery bypass grafting
