Platelet-endothelial cell interactions. The role of JAM-A for postischemic platelet-endothelial cell interactions was assessed using intravital fluorescence microscopy. Microphotographs in panels A and B demonstrate rhodamine 6G-labeled JAM-A^+/+ platelets in the hepatic microcirculation of a sham-operated JAM-A^+/+ mouse (A) and a JAM-A^+/+ mouse after hepatic I/R (B). Photomicrograph in panel C shows JAM-A^-/- platelets in the postischemic microvessels of a JAM-A^+/+ mouse. Platelets adherent in postsinusoidal venules are marked by arrows; platelets accumulated in sinusoids are labeled by arrowheads. Monitor magnification, × 500 (water immersion objective 25×/0.6 W).