苯并芘对褐菖鲉肝细胞DNA交联的影响

DNA crosslinks induced by benzopyrene in Sebastiscus marmoratus liver

以褐菖鲉(Sebastiscus marmoratus)为实验材料,设定苯并芘[B(a)P]的注射剂量梯度分别为0.00、0.05、0.50、5.00 mg/kg,分别于实验的第0、3、6天对每一条鱼进行腹腔注射,于第1、4、7天取样,测定胆汁中的B(a)P及其代谢物含量.采用荧光检测法检测B(a)P染毒后褐菖鲉肝细胞DNA-DNA交联(DDC)交联系数的变化,并用KC l-SDS沉淀法检测DNA蛋-白质交联(DPC)交联系数的变化.结果表明:(1)经注射染毒后鱼体胆汁中的B(a)P及其代谢物含量蓄积程度存在着明显的剂量效应和时间效应;(2)B(a)P的注射剂量分别为0.05、0.50 mg/kg时各时间点褐菖鲉肝细胞DDC交联系数均无显著增大(p>0.05),在5.00 mg/kg剂量组,随着时间延长DDC交联系数逐渐增大,第4天即有显著差异(p<0.05),第7天差异极显著(p<0.01);(3)B(a)P诱导DPC的趋势与DDC类似,但0.5 mg/kg剂量组在第7天DPC交联系数即出现显著增大(p<0.05).这表明B(a)P对DPC的诱导高于DDC.这为进一步研究B(a)P的遗传毒性提供了依据,并为探讨B(a)P致癌的作用机理提供了新的信息.

To investigate the effect of DNA-DNA crosslinks（DDC） and DNA-protein crosslinks（DPC） induced by benzopyrene ,intrapertioneal injections of B（a）P with a gradient of 0.00,0.05,0.50,and 5.00 mg/kg were administered to individual Sebastiscus marmoratus on days 0,3,and 6,and fish livers were collected on days 1,4,and 7.The concentrations of B（a）P and its metabolites in bile were measured,and the contents of DDC and DPC in Sebastiscus marmoratus liver were determined by fluorescence spectrophotometry and KCl-SDS assay,respectively.The results showed that：（1） The contents of B（a）P and its metabolites in bile after infection were positively correlated with dose and time;（2） when B（a）P reached 0.05 mg/kg and 0.50 mg/kg,DDC no longer significantly increased（p0.05）,and significant induction occurred on day 4（p0.05 on day 7;p0.01 in the 5 mg/kg group）;（3） The changes in the DPC content were similar to those in DDC,but in the 0.50 mg/kg group,the DPC was significantly upregulated at day 7（p0.05）.These results indicated a higher induction of DPC by B（a）P than DDC.The findings presented here provide the basis for further studies of B（a）P hereditary toxicity and provide new information for evaluation of the carcinogenic mechanism of B（a）P.