Proliferation characteristics of cultured human aortic endothelial cells and expression of adhesion molecules

Basal expression of the adhesion molecules P-selectin and ICAM-1, which mediate adhesion and transendothelial migration of leukocytes, by endothelial cells of human aorta and umbilical vein and its relationship with the proliferative behavior of these cells are studied in primary prolonged cultures. Inverse proportionality between the percentage of resting endothelial cells and those expressing the adhesion molecules in preconfluent and confluent monolayers, on the one hand, and the percentage of cells in the active cycle which do not express the adhesion molecules, on the other, is demonstrated. This relationship is one of the major causes of the in vitro functional heterogeneity of the endotheliocyte population in the expression of adhesion molecules and its adhesiveness for leukocytes.