Association of IL-8 and MCP-1 with the development of reexpansion pulmonary edema in rabbits

Background. The aim of this study is to determine the relationships between the cytokines and the inflammatory response in reexpansion pulmonary edema (RPE). Methods. We examined the cell population, epithelial permeability measured by Evans blue dye (EB), βglucuronidase and cytokine concentrations in bronchoalveolar lavage fluid (BALF) and/or blood using a rabbit RPE model. Results. We confirmed that RPE is characterized by recruitment of polymorphonuclear leukocytes (PMNs), the release of PMN granular contents into the air spaces, and increased vascular permeability. These findings were highly correlated with increased interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) concentrations in the BALF. Growth related oncogene (GRO) was detected in the BALF from only 2 of the 7 reexpanded lungs while TNFα was not detected in any rabbits. A similar but less severe inflammatory response to the reexpanded lung was found in the contralateral lung. Conclusions. IL-8 and MCP-1 may play important roles in the development of RPE; the inflammatory response is independent of TNFα and unilateral reexpansion of the lung induces an inflammatory response not only in the reexpanded lung but also in the contralateral lung.