Leukocyte responses induced by IL-1β and TNFα in cremasteric venules of PECAM-1–deficient mice.

PECAM-1–deficient and wild-type mice were treated either with intrascrotal saline or with IL-1β (30 ng) (A) or TNFα (300 ng) (B) 4 hours before the cremaster muscle was prepared for intravital microscopy. Upper and lower panels show leukocyte firm adhesion and transmigration, respectively, from the same experiments. The data represent mean ± SEM (n = 5 mice per group; *P < .05, **P < .01, ***P < .001).