L11 blocks binding of monocytoid cells to intact aortic endothelium from fat-fed rabbits. Fluorescent-labeled WEHI78/24 cells were incubated with control IgG or L11 (1 μg/10⁶ cells) for 20 minutes, added to intact aortic segments from control and cholesterol-fed New Zealand White rabbits, and allowed to bind for 30 minutes at RT under constant rotation. Following extensive washing to remove nonadherent cells, the number of adherent cells in 15 fields (totaling 1.4 cm2 ) was determined on at least five independent segments from at least two control rabbits and three cholesterol-fed rabbits in each of three experiments. The mean and standard error of the pooled data are shown.