Particulate release of MC Mediators. (A) Rat lymphoblastic leukemia-2H3 cells (a MC-like cell line), which express a TNF–green fluorescent protein fusion protein (green), incorporate TNF and other mediators, including serotonin (red), into their granules. Colocalization of these markers can be viewed in the merged image where the overlapping areas appear yellow. The construction of these cells is described in Kunder et al4 (60×/1.40 NA, oil objective). (B) A resting MC (left) and a compound 48/80-activated mast cell (right), both obtained from rat peritoneal lavage, and stained with toluidine blue (60×/1.40 NA oil objective). (C) An activated, rat peritoneal MC stained with avidin to show the granules, some of which have diffused away from the cell after release as discrete particles. Confocal images were acquired using a Nikon Eclipse TE200 microscope and EZ-4 Version 3.6 software. Bright field images were captured using a Nikon Eclipse TE200 microscope and a Nikon Coolpix 4500 camera. Additional image processing was performed using Adobe Photoshop Version 9.
