Detection of Apoptosis in Atherosclerosis and Restenosis by Terminal dUTP Nick-End Labeling (TUNEL)

Kerr and Wyllie (1) have introduced the term apoptosis to separate this special form of cell death from necrosis. When a cell receives a signal to die an apoptotic death, it goes through a series of morphological changes that can be easily observed with the light microscope. Starting from shrinkage of the cell membrane, to condensation of nuclear chromatin, cellular fragmentation, and finally the engulfment of the apoptotic bodies by neighboring cells. Although the term apoptosis was introduced only 30 years ago, typically apoptotic morphology has been described by embryologists in the beginning of this century. Embryologists recognized the need for some mechanism to counterbalance cellular proliferation during the development of organs and limbs. Apoptosis, however, is not limited to cell death during embryonic development. In recent years, apoptosis has been implicated in cell deaths caused by ionized radiation, steroid treatment, chemotherapy, ischemia-reperfusion, and in atherogenesis.