Abstract:
Hypohalous acids are generated by activated leucocytes, via the formation of H2O2 and the release of peroxidase enzymes (myeloperoxidase and eosinophil peroxidase). These species are important bactericidal agents, but HOCI (hypoclorous acid) and HOBr (hypobromous acid) have also bee implicated in tissue damage in a number of inflammatory diseases. HOSCN (hypothiocyanous acid; cyanosulfenic acid) us a milder more thiol-specific, oxidant than HOCI or HOBr and as such may be a more potent inducer of cellular dysfunction due to selective targerting of critical thiol residues on proteins. In the present study, HOCI and HOBr are shown to react rapidly with macrophage (J774A.1) cells, resulting in a greater extent if cell lysis compared with HOSCN. However, HOSCN induces apoptosis and necrosis with greater efficacy and at lower concentrations, than HOCI or HOBr.
