[An in vivo study on DNA-protein crosslinks induced by nickel chloride]

DNA-protein crosslinks (DPC) in the white blood cells (WBC) and lung tissues were detected with a new and sensitive 125I-post-labelling technique in male Sprague-Dawley rats injected peritoneally (i.p.) with nickel chloride (NiCl2). Results showed DPC in the WBC and lungs of the rats increased significantly 20 hours after acute exposure to NiCl2. Multiple small doses (10 mg/kg i.p., twice a week for three weeks) of NiCl2 had similar effects as single large dose (30 mg/kg). It suggested DPC could be used as a biomarker to reflect genotoxicity to the WBC and lungs caused by nickel compound. DPC in the WBC increased more obviously than that in the lungs after exposure to NiCl2, and both correlated to each other. It showed DPC in the WBC can be used as a surrogate to indicate genotoxic lesions in target organs.