The use of fluorescent microspheres in the study of piscine macrophage aggregate kinetics.

The kinetics of piscine liver, spleen, and kidney macrophage aggregate formation was studied in Carassius auratus using the sequential interperitoneal injection of fluorescent green and yellow microspheres. This study indicates that 1. macrophages migrating to or forming new aggregates move randomly throughout the aggregate mass and do not simply increase aggregate size by a laminating process (layer upon layer), 2. macrophages apparently form new aggregates and migrate to existing aggregates simultaneously, and 3. macrophage aggregates form in greater number and more rapidly in the spleen and kidney than in the liver.