Leukocyte responses induced by LTB4, PAF, and IL-1β in cremasteric venules of WT and JAM-A–deficient mice as observed by IVM. (A) The cremaster muscle of WT (□) or JAM-A−/− (■) mice was exteriorized for observations by IVM as detailed in “Materials and methods, Intravital microscopy.” Tissues were superfused with either saline (control) or with LTB4 or PAF (both with a solution of 10−7 M). Leukocyte responses of firm adhesion (left panel) and transmigration (right panel) after a 60-minute (LTB4) or 120-minute (PAF) superfusion period were quantified. Results are presented as means (± SEM) for n = 4–6 mice/group. (B) Mice were given intrascrotal saline (□) or intrascrotal IL-1β (50 ng/mouse; ■); 4 hours later, leukocyte responses of adhesion (left panel) and transmigration (right panel) were quantified. Results are presented as means (± SEM) for n = 6 mice/group. Statistically significant differences between control and stimulated groups are shown by asterisks (*P < .05, **P < .01, and ***P < .001). Additional statistical comparisons are indicated by lines and number signs (#P < .05).
