Objective: To study DNA damages of liver cells in rats exposed to vinyl chloride monomer (VCM), and the expressions of DNA damage repair enzymes including O(6)-methyl guanine-DNA methyl transferase (MGMT), X-ray repair cross-complementing group 1 (XRCC1) and X-ray repair cross-complementing group 3 (XRCC3); and to explore the repair mechanism of DNA damage induced by VCM.
Methods: Rats were exposed to VCM by intraperitoneal injection. DNA damages were detected by single cell gel electrophoresis (comet assay). The expressions of DNA damage repair enzymes were measured by immunohistochemical methods.
Results: The percentages of comet cells in low, moderate, and high dose groups (11.75%, 12.38%, and 17.63%, respectively) were greater than that of control (5.67%). The latter two groups were significantly different from that of control (P < 0.05, P < 0.01). The expressions of MGMT and XRCC1 decreased, and XRCC3 increased with the dose of VCM increased. DNA damage was correlated with the expression of XRCC3 (r = 0.438, P = 0.067).
Conclusion: VCM can cause DNA damage of liver cells with dose-response relationship. DNA damage repair enzymes take part in the repairing of DNA damage induced by VCM.