Binding of 1-nitro[14C]pyrene to DNA and protein in cultured lung macrophages and respiratory tissues.

Binding of 1-nitro[14C]pyrene (1-NP) or its metabolites to cellular DNA and protein in cultures of rabbit alveolar macrophages and lung and tracheal tissues was examined. DNA binding was highest in tracheal tissue (136.9 +/- 18.3 pmol 1-NP/mg DNA). DNA binding in macrophages and lung tissue was one-fifth of the level observed in tracheal tissue. Also, 1-NP was bound to cellular protein in tracheal and lung tissues, and at a lower level in macrophages. Co-cultivation of the macrophages with lung and tracheal tissues decreased the DNA binding in tracheal tissue and increased the protein binding in macrophages. This study shows that lung cells and tissue are capable of binding 1-NP or its metabolites to DNA and protein.