[Cardiovascular diseases and oxidative stress]

We are always exposed to oxidative stress, when oxygen is used for production of energy for our daily activity. Mild to moderate oxidative stress affects intracellular signal transduction, accelerating the protective system for oxidation; thereby inflammatory cytokines are produced leading to increased levels of acute phase proteins. Vascular endothelial cells protect the vessels from oxidative stress, however, when they are damaged by shear stress to the vascular wall, oxidation spreads into the subendothelial matrix, leading to oxidation of low-density lipoproteins(LDL) accumulated there. Oxidized LDL is easily and abundantly taken up into macrophages via the scavenger receptors such as LOX-1, which leads to the formation of atherosclerosis. Markers for oxidative stress in vivo are being sought for prevention and treatment of cardiovascular diseases. There are a number of parameters as candidates, and among them, we chose biopyrrins, oxidative products of bilirubin, and have studied their role in coronary heart diseases. Urinary excretions of biopyrrins are significantly elevated in patients with coronary arterial stenosis and with ischemic changes on electrocardiogram. Similar finding have been obtained in patients with vasospastic angina. These findings suggest that markers for oxidative stress will be a good laboratory test for evaluation of coronary heart diseases.