Oxidative stress is important in the genesis of atherosclerotic lesions.
This study was designed to see whether MTs occur in human atherosclerotic plaques and which cell types are involved. MT immunoreactivity was seen only within SMCs, which occurred usually in small clusters and were found mostly near lipid cores and occasionally in the media. Electron microscopy was done to evaluate the subtype of MT-positive cells and revealed that the majority consisted of synthetic SMCs. The observation that MT was expressed only in SMCs, particularly those of synthetic phenotype, suggests that MT plays a role in protecting these active matrix-producing cells. In case of oxidative stress, however, the balance between ROS production and scavenging is impaired either by an increase in the amount of ROS or by a decrease in scavenger capabilities.