Pimonidazole hydrochloride accumulates in hypoxic cells via covalent binding with macromolecules or by forming reductive metabolites after the reduction of its nitro group. It can be used for qualitative and quantitative assessment of tumor hypoxia. Pimonidazole hydrochloride is a novel hypoxia marker for the complementary study of tumor hypoxia and cell proliferation in tumors.
Pimonidazole, the exogenous hypoxia marker, is a 2-nitroimidazole compound, which forms covalent bonds with cellular macromolecules at oxygen levels below 1.3%[3].
Pimonidazole is a 2-nitroimidazole that is reductively activated specifically in hypoxic cells and forms stable adducts with thiol groups in proteins, peptides, and amino acids. Additionally, the amount of pimonidazole that is detected is directly proportional to the level of hypoxia within tumors in vivo.