In vivo measurements of endothelial cell adhesion molecule expression

The essential role of endothelial CAMs in the recruitment of leukocytes to sites of inflammation has been extensively studied in recent years. The development of techniques such as the radiolabeled MAb method that is described in this chapter has enabled investigators to quantitatively assess the expression of endothelial CAMs in different regional vascular beds. Although the study of adhesion molecules in vitro has extended our knowledge of the mechanisms and mediators of endothelial CAM function, the newly acquired in vivo data would indicate that findings resulting from experiments on monolayers of cultured endothelial cells may not accurately depict inflammatory events that occur in vivo. Thus, additional work is needed to more fully define the conditions that account for the discrepencies noted between the in vivo and in vitro models of endothelial CAM expression.