Participation of macrophages in chloramphenicol-potentiated carrageenin-induced peritonitis in rats

ABSTRACT

1. We investigated the possible potentiating effect of chloramphenicol succinate (30 mg/kg, every 12 h for 4 days, ip) on the response of polymorphonuclear neutrophils to carrageenin (150 micrograms, ip) or dextran (100 micrograms, ip) in the peritoneal cavity of male Wistar rats (180-230 g; N = 12 in each group). 2. Chloramphenicol potentiated the cell migration induced by carrageenin (35 per cent ) but not that induced by dextran. Previous macrophage depletion in the peritoneal cavity by washing with sterile saline abolished the cell response, whereas a previous thioglycollate-induced increase in macrophage numbers enhanced the potentiating effect (60 per cent ). 3. These results suggest that the potentiating effect on polymorphonuclear neutrophil migration induced by chloramphenicol may be related to chemotactic factors released by macrophages