Long-term cell culture of resident peritoneal macrophages from red sea bream Pagrus major

We tried to culture the resident peritoneal macrophage (RPM) of red sea bream (RBS) and obtained transferable cultured cells, when cultivated using RPMI1640 supplemented with 0.4% NaCl and 20% fetal bovine serum at 30 degrees C in 5% CO2. The cells had phagocytic activity against Latex beads and had acid phosphatase and nonspecific esterase activities, both of which are principal characteristics of RBS RPM. Electron microscopically, the cells had slender microvilli, micropinocytic vesicle-like vacuoles, and microfibrils, similar to RSB RPM. The cells had receptors for RSB IgM on the cell surface. The cultured cells migrated to 10(-8) M N-formylmethionyl leucocyl phenylalanine (FMLP) and the supernatants of the cultured cells. The results suggest that resident peritoneal macrophages produce and release chemotactic factor-like substance (s) in the abdominal cavity.