SD大鼠灌胃盐酸丙卡巴肼与乌拉坦的多脏器碱性彗星实验研究

Study of Alkaline Comet Assay at Various Tissues in SD Rats with Intragastric Administration of Procarbazine Hydrochloride and Ethyl Carbamate

目的:通过碱性彗星实验评价盐酸丙卡巴肼(PCZ)和乌拉坦(EC)对大鼠不同脏器的DNA损伤效应,验证多脏器碱性彗星实验的可行性。方法:取30只SD大鼠按体质量随机分成6组,每组5只,分别为阴性对照组(超纯水)、PCZ 75 mg/kg组、PCZ150 mg/kg组、EC 400 mg/kg组、EC 800 mg/kg组以及阳性对照组(N-乙基-N-亚硝基脲,40 mg/kg)。大鼠连续灌胃给药4 d,实验期间观察其临床症状并记录体质量,末次给药后3 h内处死大鼠,称肝、肾、肺质量,收集肝、肾、肺及外周血淋巴细胞,制备成单细胞悬液进行碱性彗星实验。样本分别经裂解、解旋、电泳、染色等步骤后,使用Komet 6.0软件进行图像分析尾DNA含量百分率(尾DNA%)、尾距。结果:与阴性对照组比较,PCZ 75、150 mg/kg组和阳性对照组大鼠给药4 d后体质量和肝、肾质量均明显降低(P<0.05或P<0.01),EC 800 mg/kg组大鼠给药4 d后仅体质量明显降低(P<0.05或P<0.01),其余差异均无统计学意义(P>0.05)。与阴性对照组比较,PCZ 75、150 mg/kg组和阳性对照组大鼠肝、肾、肺和外周血淋巴细胞的尾DNA%和尾距均明显增加(P<0.05或P<0.01),其中PCZ对肝、肺的影响程度更明显;EC 800 mg/kg组大鼠肝、肾和外周血淋巴细胞的尾DNA%和尾距均明显增加(P<0.05或P<0.01),EC 400 mg/kg组大鼠仅肾组织的尾DNA%和尾距明显增加(P<0.05)。结论:PCZ诱导的细胞DNA损伤较强,肝和肺是其遗传毒性作用的易感器官;EC诱导的细胞DNA损伤相对较弱,肾是其遗传毒性作用最敏感的器官。

OBJECTIVE:To evaluate the DNA damage response of procarbazine hydrochloride(PCZ)and ethyl carbamate(EC)to different tissues in rats by performing alkaline comet assay,to validate the feasibility of alkaline comet assay of various tissues.METHODS:Totally 30 SD rats were randomly divided into 6 groups according to body weight,with 5 rats in each group,such as negative control group(hyperpure water),PCZ 75 mg/kg group,PCZ 150 mg/kg group,EC 400 mg/kg group,EC 800 mg/kg group,positive control group(N-ethyl-N-nitrosourea 40 mg/kg).Those rats were given relevant medicine intragasttrically for 4 d;clinical symptoms of rats were observed and body weight was recorded during experiment.Within 3 h after last medication,the rats were sacrificed;liver,renal and lung weight were weighed;liver,kidney,lung and peripheral blood lymphocytes were collected.The single cell suspension was prepared to perform alkaline comet assay.After lysis,unwind,electrophoresis and dying,tail DNA%and tail distance of samples were analyzed by Komet 6.0 software.RESULTS:Compared with negative control group,body weight,liver and renal weight of rats were decreased significantly in PCZ 75 mg/kg group,PCZ 150 mg/kg group and positive control group 4 d after medication(P<0.05 or P<0.01).Body weight of rats were decreased significantly in EC 800 mg/kg 4 d after medication(P<0.05 or P<0.01);there was no statistical significance(P>0.05).Compared with negative control group,tail DNA%and tail distance in liver,kidney and peripheral blood lymphocytes were increased significantly in PCZ 75 mg/kg group,PCZ 150 mg/kg group and positive control group(P<0.05 or P<0.01);PCZ showed more significant effects on liver and lung.Tail DNA%and tail distance of liver,kidney and peripheral blood lymphocytes were increased significantly in EC 800 mg/kg group(P<0.05 or P<0.01),and tail DNA%and tail distance of renal tissue was increased significantly in EC 400 mg/kg group(P<0.05).CONCLUSIONS:PCZ induced stronger DNA damage;liver and lung are the major genotoxicity target of PCZ.EC-induced DNA damage is relatively weak,and kidney is the most sensitive organ for EC-induced genotoxicity.