苯并芘对大鼠胎盘组织CYP450、GSH-PX活性及胎鼠外周血BPDE-DNA加合物浓度的影响

BaP Effect on the Activities of Cytochrome P450,GSH and PX in Placental Tissues of Rats and the Concentration of BPDE-DNA in Peripheral Blood of Fetal Rats

目的探讨苯并芘(benzo[a]pyrene,BaP)对大鼠胎盘组织细胞色素P450酶(cytochrome P450,CYP450)、谷胱甘肽过氧化酶(glutathione peroxidase,GSH-PX)活性及胎鼠外周血二羟环氧苯并芘[benzo(a)pyrene-7,8-Dihydrodiol-9,10-Epoxide,BPDE]-DNA加合物浓度的影响。方法选择性成熟SD大鼠120只据雌雄不同随机分为空白组及低、中、高浓度BaP组,每组30只,雌雄分开饲养,空白组雌鼠灌胃橄榄油,低、中、高浓度BaP组雌鼠分别每日灌胃BaP 0.5、1.0、2.0 mg/kg,15 d后雌雄鼠同笼,第2天发现精液栓者为受孕,将受孕鼠继续前述灌胃14 d后处死,取胎盘组织测定CYP450、GSH-PX活性并检测胎鼠外周血BPDE-DNA加合物浓度。结果与空白组比较,低、中、高浓度BaP组胎盘组织中CYP450活性及胎鼠外周血中BPDE-DNA加合物浓度升高,胎盘组织中GSH-PX活性降低,差异均有统计学意义(P<0.05)。低、中、高浓度BaP组胎盘组织中CYP450活性及胎鼠外周血中BPDE-DNA加合物浓度随BaP浓度增加逐渐增强或升高,胎盘组织中GSH-PX活性随BaP浓度增加逐渐降低,3组间比较差异均有统计学意义(P<0.05)。相关性分析结果显示胎盘组织中CYP450活性与GSH-PX活性呈负相关,与胎鼠外周血中BPDEDNA加合物浓度呈正相关。结论 BaP能增强或升高胎盘组织中CYP450活性及胎鼠外周血中BPDE-DNA加合物浓度,降低胎盘组织中GSH-PX活性。

Objective To explore the benzo[a]pyrene（BaP）effect on the activities of cytochrome P450（CYP450） and glutathione peroxidase（GSH-PX）in placental tissues of rats and the concentration of BPDE-DNA[benzo（a）pyrene-7,8-Dihydrodiol-9,10-Epoxide,BPDE]in peripheral blood of fetal rats. Methods Viripotent 120 SD rats were randomly divided into control group（n=30）,low concentration BaP group（n=30）,middle concentration BaP group（n=30）and high con-centration BaP group（n=30）,and female rat and male rats were raised respectively. Rats were lavaged with olive oil in con-trol group,and different concentrations BaP（0. 5,1. 0 and 2. 0 mg/kg）in the other three groups respectively,and males were mated with females after treatment for 15 d. Rats,which were found with semen plug at the second day,were continuous-ly lavaged with the same methods previous for 14 d and killed,and then the activities of CYP450 and GSH-PX in placental tis-sues and the concentration BPDE-DNA in peripheral blood of fetal rats were detected. Results The activity of CYP450 and the concentration of BPDE-DNA in BaP groups were significantly higher,while the GSH-PX activity was significantly lower than those in control group（P﹤0. 05）. In BaP groups,the activity of CYP450 and the concentration of BPDE-DNA gradually increased with the increased BaP dose,while the GSH-PX activity gradually decreased with the increased BaP dose,and the differences in the three groups were statistically significant（P ﹤0. 05）. The correlation analysis showed that the activity of CYP450 was negatively correlated with the GSH-PX activity,and was positively correlated with BPDE-DNA adduct concentra-tions. Conclusion BaP may enhance the activity of CYP450 and the concentration of BPDE-DNA in peripheral blood of fetal＆amp;nbsp;rats,and decrease the GSH-PX activity in placental tissues.