The role of alveolar macrophage activation in rats with lung injury associated with acute necrotizing pancreatitis / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To discuss the role of alveolar macrophage activation in rats with acute necrotizing pancreatitis (ANP) associated with lung injury.</p><p><b>METHODS</b>30 adult Sprague-Dawley rats were randomly divided into five groups (n = 6) normal control group, one-hour group, three-hour group, six-hour group and twelve-hour group after ANP induction. ANP was induced by intraductal administration of 3% sodium taurocholate, while the normal control received an infusion of physiological saline. Alveolar macrophages were harvested by bronchoalveolar lavage. The protein content of lavage fluids, the myeloperoxidase of lung tissue (MPO), and tumor necrosis factor alpha (TNFalpha) and nitric oxide (NO) secreted by alveolar macrophages were examined. The expression of TNFalpha mRNA and inducible nitric oxide synthase (iNOS) mRNA was measured with reverse transcription-polymerase chain reaction technique. Histology of the lung and pancreas was scored in a blinded fashion.</p><p><b>RESULTS</b>Lung injury was gradually aggravated with disease progression. The level of myeloperoxidase of lung tissue and protein content of bronchoalveolar lavage fluids increased progressively and reached the peak at 12 hour [(10.78 +/- 0.58) U/g for MPO and (2 011.0 +/- 105.5) micro g/ml for protein respectively]. TNFalpha and NO secreted by alveolar macrophages were gradually elevated and peaked on the sixth hour, the maximums were (1 624.2 +/- 149.2) pg/ml and (88.8 +/- 6.5) micro mol/L respectively, but decreased on the twelfth hour. The expression of TNFalpha mRNA and iNOS mRNA was similar with the changes of TNFalpha and NO, upregulated after induction of acute necrotizing pancreatitis and reached their peaks on the sixth hour, then downregulated on the twelfth hour. All the parameters of ANP groups compared to control group were statistical significant (P < 0.05). The histology scores demonstrated an increasing damage of the lung. The expression of TNFalpha mRNA and iNOS mRNA is closely related to lung injury (r = 0.67 for TNFalpha mRNA and r = 0.64 for iNOS mRNA respectively, P < 0.01).</p><p><b>CONCLUSION</b>The activation of alveolar macrophage may play an important role in lung injury associated with acute necrotizing pancreatitis.</p>