The effect of monoclonal antibodies against adhesion molecules on the development of endotoxin-induced uveitis (EIU) and interleukin-1 (IL-1)-enhanced EIU were studied. When endotoxin or IL-1 was injected into C3H/HeN mice, the expression of intercellular adhesion molecule-1 (ICAM-1) on the ciliary body was up-regulated as determined by immunohistochemical assay. However, these agents did not alter lymphocyte function-associated antigen-1 (LFA-1) expression on leukocytes when whole blood cells were analyzed with flow cytometry. Monoclonal anti-ICAM-1 antibody or anti-LFA-1 antibody was intraperitoneally administered to C3H/HeN mice simultaneously with endotoxin, and the effect on the development of EIU was studied. The cell number in aqueous humor and frequency of posterior synechiae were markedly decreased in EIU when either antibody was administered. However, protein concentration in the aqueous humor was not statistically reduced by the injection of these antibodies. In the model of IL-1 enhanced EIU, not only the cell number and frequency of posterior synechiae but also protein concentration were decreased. Moreover, there were no differences between these two antibodies in the effect on EIU, whereas anti-LFA-1 antibody was more effective than anti-ICAM-1 antibody in IL-1-enhanced EIU.