In vitro activity of aminoglycosides on the respiratory burst response in human polymorphonuclear neutrophils

In response to phagocytosis of microbes or chemical stimuli, neutrophils ge nerate reactive oxygen species which represent the major bactericidal mecha nism of these cells. We have investigated the influence of aminoglycosides (amikacin, gentamicin, netilmicin and tobramycin), antibiotics with a marke d concentration-dependent killing effect, on the human neutrophil oxidative burst represented by the release of hydrogen peroxide. This study was perf ormed using time-dependent cellular experiments and a cell-free system. In the cellular model, 2-h incubation with amikacin (ranging from 10 mg/l to 1 g/l), enhanced hydrogen decreased. No significant effects were observed wi th the other aminoglycosides at concentrations ranging from 10 mg/l to 2.5 g/l. The pro-oxidant activity of amikacin may be due to a cellular mechanis m through oxidative metabolism of human neutrophils as demonstrated in the cell washing experiment, whereas the antioxidant activity observed for high er concentrations may be a result of a scavenging effect as demonstrated in the cell-free system. The enhanced of hydrogen peroxide production observe d for therapeutic concentrations of amikacin could be a beneficial effect f or neutrophil bactericidal functions. (C) 1998 Prous Science. All rights re served.