Enhanced expression of cytokine-induced neutrophil chemoattractant (CINC) by bronchoalveolar macrophages in cerulein-induced pancreatitis rats

The role of bronchoalveolar macrophages (BAMs) in the aggravation of cerulein-induced pancreatitis was studied by measuring expression of cytokine-induced neutrophil chemoattractant (CINC) in vitro. Pancreatitis was induced by four intramuscular injections of cerulein (50 mu g/kg at 1-hr intervals). Pancreatitis rats were injected intraperitoneally with 30 mg/kg lipopolysaccharide (LPS) 6 hr following the first cerulein injection as a septic challenge. Rats were divided into four groups: group I, nonpancreatitis without LPS; group II, pancreatitis without LPS; group III, nonpancreatitis with LPS; and group IV, pancreatitis with LPS. Hyperactivity of BAMs in response to LPS was assessed as a function of in vitro CINC production. CINC concentrations of the serum and bronchoalveolar lavage fluid in group IV were significantly higher than those in groups I, II, and III. BAMs in group II harvested 6 hr following the first cerulein injection had significantly greater CINC production than those in group I. Northern blot analysis revealed abundant CINC mRNA transcripts in BAMs from groups III and IV. Additionally, myeloperoxidase activity in the lung of group IV rats 8 and 12 hr following the first cerulein injection was significantly higher than that in group I, II, and III rats. Significant differences in static lung compliance in group IV were found compared with groups I, II, and III. These results indicate that BAMs from rats with cerulein-induced pancreatitis were primed and had enhanced release of CINC following LPS exposure. Enhanced expression of CINC may modulate the pathogenesis of pancreatitis-associated lung injury complicated with sepsis.