Based on the previous findings, the objective of this research was to study the potential effect of glyceryl trinitrate (GTN), a donor of nitric oxide and NG-nitroarginine methyl ester (l-NAME), a nitric oxide inhibitor on acute liver damage and tumor promotion markers such as ornithine decarboxylase (ODC) activity and [3H]-thymidine incorporation in rats induced by a single necrogenic dose of TAA. The gene discussed is ODC1; the disease is neoplasm.