Role of endothelial integrity in atherosclerosis.

Recent advances in endothelial biology have made it essential that we carefully define the concept of "endothelial injury." Frank denudation may not play an important role, indeed may not exist because of the ability of the endothelium to rapidly replace desquamating cells. Less dramatic forms of injury which may be of interest include alterations of endothelial cell functions in replicating cells as well as alterations in function which may occur independent of any cell loss. This last category receives new emphasis today because of the rapid increase in the number of functions identified in endothelial cells. These include the apparent ability of endothelial cells to synthesize a growth factor which can stimulate smooth muscle proliferation in the absence of the platelet derived growth factor.