苯亚急性染毒对大鼠造血系统的影响及其机制

Effects of sub-acute exposure to benzene on hematopoietic system in rats

目的探讨苯亚急性染毒对大鼠造血系统的影响及其机制。方法将30只雄性SD大鼠随机分为空白对照组、溶剂对照组、苯低剂量组、苯中剂量组和苯高剂量组,每组6只。苯低、中、高剂量组分别按照体质量给予200、400、800 mg/kg苯溶液灌胃,空白对照组未经任何处理,溶剂对照组给予等量玉米油灌胃;均1次/d,连续处理28天。采用全自动血细胞分析仪检测血常规,处死大鼠后计算肝脏、脾脏系数,观察股骨病理改变及骨髓、外周血细胞形态改变;采用单细胞凝胶电泳法检测骨髓及外周血细胞DNA损伤情况,记录尾矩(TM)和Olive尾矩(OTM)。结果苯低、中、高剂量组白细胞均低于空白对照组和溶剂对照组,苯高剂量组红细胞均低于其余各组,苯中、高剂量组血红蛋白均低于其余各组(P均<0.05);各组间血小板比较差异均无统计学意义(P均>0.05)。各组肝脏、脾脏系数比较差异均无统计学意义(P均>0.05)。空白对照组、溶剂对照组股骨病理改变及骨髓、外周血细胞形态改变基本一致;苯低、中、高剂量组股骨病理显示造血组织面积减小,骨髓、外周血细胞有较多中毒颗粒、空泡,随着苯染毒剂量的增加,上述改变越明显。苯低、中、高剂量组骨髓及外周血细胞TM和OTM依次升高,且均高于空白对照组、溶剂对照组(P均<0.01)。结论苯亚急性染毒对大鼠骨髓具有毒性损伤作用,且呈浓度依赖性,可能与其导致外周血、骨髓细胞发生DNA损伤有关。

Objective To investigate the effect of sub-acute exposure to benzene on hematopoietic system in rats and to explore its related mechanism. Methods Thirty male SD rats were randomly divided into the blank control group,solvent control group,low-dose benzene group,medium-dose benzene group and high-dose benzene group,with 6 rats in each group. Benzene exposure groups were given 200,400 and 800 mg / kg benzene solution respectively according to the body mass,the blank control group was not treated,and the solvent control group was given equal volume of corn oil,once a day and for 28 days. Routine blood test was analyzed by automatic blood-counter system. We killed the rats,then calculated the coefficient of liver and spleen,and observed the pathological changes of the femur and the morphological changes of bone marrow and peripheral blood cells. DNA damage of bone marrow and peripheral blood cells were detected by single cell gel electrophoresis（ SCGE）,and we recorded the tail moment（ TM） and Olive tail moment（ OTM）. Results The WBC of low-dose,medium-dose and high-dose benzene groups were lower than that of the blank control group and the solvent control group（ P〈 0. 05）. The RBC in the high-dose benzene group was lower than the other groups,and the hemoglobin（ Hb） in the medium-dose and high-dose benzene groups was lower than that of the other groups（ P 〈0. 05）. There was no significant difference in PLT among these groups（ all P〉 0. 05）. There were no significant differences in liver and spleen coefficients among these groups（ all P〉 0. 05）. In the blank control group and solvent control group,the morphological changes of the bone marrow and peripheral blood cells and the pathologic changes of the bone marrow were basically consistent. The pathological changes showed that in the three benzene groups,the area of hematopoietic tissue was decreased,there were more toxic particles and vacuoles in the bone marrow and peripheral blood cells,meanwhile,with the increased dose of benzene,the above changes were more significant. Compared with the blank control group and solvent control group,TM and OTM were increased in turn in the three benzene groups（ P〈 0. 01）. Conclusion Aub-acute exposure to benzene has a toxic effect on bone marrow of rats with a dose-dependent manner,which may be rated to DNA damage in peripheral blood and bone marrow cells.