The Journal of immunology : official journal of the American Association of Immunologists
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The role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the pathogenesis of acute lung injury in rats after intrapulmonary deposition of IgG immune complexes or intratracheal administration of LPS has been assessed. Critical to these studies was the cloning and functional expression of rat MIP-1 alpha. The resulting product shared 92% and 90% homology with the known murine sequence at the cDNA level and protein level, respectively. ⋯ Under such conditions, in both models TNF-alpha content in BAL fluids was substantially reduced as compared with BAL fluids from positive control animals. These findings suggest that rat MIP-1 alpha plays an important role in the development of lung injury in these neutrophil-dependent models. The role of MIP-1 alpha seems to be related to production of TNF-alpha, which in turn up-regulates vascular adhesion molecules required for neutrophil influx.