Fig. 1. Impaired interstitial migration of extravasated leukocytes in vivo in JAM-A-deficient mice. (A) In vivo RLOT microscopic image of a postcapillary venule in the inflamed mouse cremaster muscle. Tissue distribution of transmigrated leukocytes was quantified in two regions of interest (ROIs), one close and one distant to the vessel (indicated by the two boxed regions). (B) Quantitative analysis of tissue distribution of transmigrated leukocytes after 60 minutes of stimulation with LTB4. In JAM-A-deficient mice, a significantly smaller proportion (41.9±4.1%) of transmigrated leukocytes is found in the ROI distant to the analyzed postcapillary venule (>25 µm distance from the venule) compared with a similar region in JAM-A^+/+ mice (58.5±3.1%; n=6; mean ± s.e.m.; ^*P<0.05 vs JAM-A^+/+).