N-ACETYLCYSTEINE INHIBITS IL-1-ALPHA-INDUCED IL-8 SECRETION BY BRONCHIAL EPITHELIAL-CELLS

The protective effects of N-acetylcysteine (NAC) have been documented in experimental and clinical acute lung injury. However, the effect of NAC on the secretion of interleukin-8-(IL-8), which is an important m ediator of the pathogenesis of acute lung injury through the recruitme nt of neutrophils, has not been determined. In the present study, ther efore, we examined the effect of NAC on IL-8 secretion by IL-1a-stimul ated bronchial epithelial cells. NAC inhibited IL-8 secretion by bronc hial epithelial cells in a dose-dependent manner. In addition, the str ucturally unrelated antioxidants, butylated hydroxyanisole (BHA) and p yrrolidine dithiocarbamate (PDTC) also effectively inhibited secretion . These results indicated that an antioxidant-sensitive mechanism migh t be involved in inhibition of IL-8 secretion by IL-1a-stimulated bron chial epithelial cells. The protective effects of NAC on acute lung in jury have been suggested to be due to scavenging reactive oxygen inter mediates (ROIs) and stimulation of glutathione synthesis. In addition to this, our results may provide an alternative explanation for the ef ficacy of NAC on acute lung injury.