CALL FOR PAPERS Leukocyte Inflammatory Mediators and Lung Physiology Antimacrophage chemokine treatment prevents neutrophil and macrophage influx in hyperoxia-exposed newborn rat lung

00414.2002.—Macrophage-derived cytokines may provoke the in-flammatory response in lung injury. Because macrophage influx is a prominent feature of the cellular inflammatory response accompany-ing the development of bronchopulmonary dysplasia, we hypothe-sized that blocking macrophage influx would reduce overall cellular influx and oxidative damage. Newborn rats were exposed at birth to 95 % O2 or air for 1 wk, and hyperoxia-exposed pups were injected with anti-monocyte chemoattractant protein-1 (MCP-1) or IgG control on days 3–5. MCP-1 was increased in bronchoalveolar lavage fluid and in histological sections from the 95 % O2-exposed, IgG-injected pups compared with air-exposed controls. At 1 wk, anti-MCP-1-treated pups had reduced leukocyte numbers, both macrophages and neutrophils, in bronchoalveolar lavage fluid compared with IgG-treated controls. Cytokine-induced neutrophil chemoattractant-1, the rat analog of IL-8, was not significantly decreased in lavage fluid bu