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

Area of Science:

• Toxicology
• Environmental Health
• Biochemistry

Background:

• 1-nitropyrene (1-NP) is a polycyclic aromatic hydrocarbon found in environmental pollutants.
• Understanding the interaction of 1-NP with cellular components is crucial for assessing its toxicity.

Purpose of the Study:

• To quantify the binding of 1-NP and its metabolites to DNA and protein in rabbit alveolar macrophages, lung, and tracheal tissues.
• To investigate the influence of co-cultivation on 1-NP binding within these cellular systems.

Main Methods:

• Incubation of rabbit alveolar macrophages, lung, and tracheal tissues with radiolabeled 1-NP.
• Measurement of 1-NP binding to cellular DNA and protein using established biochemical assays.
• Co-cultivation experiments to assess cell-cell interactions on binding.

Main Results:

• Tracheal tissue exhibited the highest DNA binding of 1-NP (136.9 +/- 18.3 pmol 1-NP/mg DNA).
• DNA binding in macrophages and lung tissue was approximately one-fifth of that in tracheal tissue.
• 1-NP also bound to cellular protein, with higher levels in tracheal and lung tissues compared to macrophages.
• Co-cultivation altered binding patterns, decreasing tracheal DNA binding and increasing macrophage protein binding.

Conclusions:

• Rabbit lung cells and tissues are capable of binding 1-NP or its metabolites to both DNA and protein.
• Cellular interactions, as observed in co-cultivation, can modulate the binding of 1-NP to macromolecules.