胆红素拮抗间二硝基苯致大鼠肝细胞DNA氧化损伤作用

目的]探讨胆红素拮抗间二硝基苯(m-DNB)诱导大鼠肝细胞DNA氧化损伤作用。方法]原代培养大鼠肝细胞与不同剂量m-DNB孵育,细胞色素C还原法和电子顺磁自旋捕获法观察m-DNB染毒大鼠肝细胞超氧阴离子自由基()和羟自由基(OH?)生成;以单细胞凝胶电泳和氚胸腺嘧啶(3H-TdR)掺入法分别观察m-DNB对大鼠肝细胞DNA损伤和合成抑制情况,分析胆红素干预对以上情况的影响。结果]随m-DNB剂量增加,大鼠肝细胞和OH?水平、DNA受损细胞数和细胞DNA断裂程度增加,3H-TdR掺入量下降,具有较明显的剂量-反应关系(P<0.01)。10μmol/L胆红素干预可明显减低m-DNB致大鼠肝细胞和OH?水平、降低DNA受损细胞数和细胞DNA断裂程度、拮抗m-DNB对大鼠肝细胞DNA合成的抑制(P<0.01)。结论]胆红素可拮抗m-DNB诱导大鼠肝细胞活性氧导致的DNA氧化损伤、减轻m-DNB对大鼠肝细胞DNA合成的抑制作用。

The Antagonistic Effect of Bilirubin Against the m-DNB Induced Oxidative Stress, DNA Damage and Synthesis Inhibition in Primary Culture Rat Hepatocyte

Objective] To study the effects of bilirubin on the oxidative DNA damage induced by m-dinitrobenzene (m-DNB) in primary culture of rat hepatocyte. Methods] Inhibition of by bilirubin and OH? generation on rat hepatocyte induced by m-DNB were determined by cytochrome C reduction and ESR assay. The antagonistic effect of bilirubin on rat hepatocyte DNA injury and synthesis inhibition induced by m-DNB were determined by single cell electrophoresis and 3H-TdR incorporation method. Results] m-DNB may induce rat hepatocyte and OH? generation,DNA injury and synthesis inhibition significantly in a dose-dependent manner;bilirubin may obviouly depress the and OH? production,attenuate DNA damage and synthesis inhibition in rat hepatocyte induced by m-DNB. Conclusion] Bilirubin may play a protective role on rat hepatocyte exposed to m-DNB by means of eliminating and OH?,decreasing oxidative DNA injury and inhibiting DNA synthesis.