Lipopolysaccharide Tolerance in Relation to Intrabronchial Influx of Neutrophils in the Rat.

Lipopolysaccharide (LPS) is a potent chemotactic component for poly-morphonuclear leukocytes (PMN, neutrophils). Since LPS tolerance was first de-scribed, many studies have been reported about the hyporesponsiveness in vitro corresponding to attenuating production of proinflammatory cytokines. We hypothesized that in vivo daily exposure to LPS stimuli impairs neutrophil accumulation in the rat airway. Interleukin 8 (IL-8) and/or CXC-chemokine, a neutrophil chemoattractant and activating cytokine, have been implicated as proin-flammatory mediators in gram-negative respiratory tract infections. It is possible that the tolerance to LPS has occurred in relation to this chemoattractant cytokine production. [ABSTRACT FROM AUTHOR]