Effect of antibiotics on rat leukocyte function.

Many antibiotics are used to treat infection in clinical practice. Actions of these drugs involve specific immune enhancement and improved overall phagocytic and bactericidal capacities of polymorphonuclear leukocytes and macrophages at the site of infection. In this study, we examined the effects of antibiotics on chemotaxis and phagocytosis by reacting macrophages with 7 different antibiotics, specifically ampicillin (ABPC), cephalexin (CEX), cefotiam (CTM), amikacin (AMK), clindamycin (CLDM), tetracycline (TC) and bleomycin (BLM). At 1 microgram/ml, there were significant differences in chemotaxis between control and experimental groups treated with agents other than ABPC and CEX (CLDM: p < 0.05, AMK: p < 0.01, CTM, TC and BLM: p < 0.001). At 10 micrograms/ml, there were significant differences in chemotaxis between the control group and all treated groups (ABPC and CLDM: p < 0.01, CEX, CTM, AMK, TC and BLM: p < 0.001). At 100 micrograms/ml, all antibiotics significantly inhibited chemotaxis (p < 0.001). Phagocytosis was evaluated by determining both the ratio and index of phagocytosis. There was a significant difference in the phagocytosis ratio between the control group and the group treated with 10 micrograms/ml of BLM (p < 0.001). At 100 micrograms/ml, all agents but ABPC significantly reduced phagocytosis in a dose-dependent manner. Agents other than ABPC similarly reduced the phagocytosis index. Significant differences were noted between the control group and groups treated with BLM or AMK (BLM: 10 micrograms/ml: p < 0.01, 100 micrograms/ml: p < 0.001, AMK: 100 micrograms/ml: p < 0.01).