苯经呼吸道染毒致大鼠的生殖毒性

The Reproductive Toxicity of Benzene Exposured by Respiratory Tract in Rats

目的探讨苯经呼吸道染毒致大鼠的生殖毒性作用。方法清洁级SD大鼠48只,雌、雄各半,随机分为4组:对照组、低(5 mg/m^3)、中(10 mg/m^3)、高(15mg/m^3)浓度苯染毒组;对照组动物吸入染毒柜内的空气,各染毒组动物吸入静式染毒柜内相应浓度的苯蒸气,每天2 h,连续染毒35天,染毒完成后第2天剖杀动物,分别检测雌、雄大鼠相关生殖毒性指标。结果中、高浓度苯可使雄鼠睾丸、附睾脏器系数降低,高浓度苯可使雌鼠卵巢脏器系数降低(P<0.05);各浓度苯致大鼠精子数量减少,分别为16.23、15.61、14.05(×10~7/附睾),与对照组比较差异均有显著性(P<0.05),中、高浓度苯可使精子活动率降低,精子畸形率增高,与对照组比较,差异均有显著性(P<0.05);中、高浓度苯致雄鼠血清睾酮降低,雌鼠FSH、LH、E_2下降(P<0.05);睾丸组织出现不同程度的曲细精管、精母细胞病理损害,随苯染毒浓度增加,病理损害越明显。结论 10～15 mg/m^3浓度苯经呼吸道染毒可致雌、雄大鼠生殖系统损伤作用。

Objective To investigate the reproductive toxicity of benzene exposured by respiratory tract in rats. Methods 24 male and 24 female SD rats of clean grade were divided randomly and averagely into 4 groups respectively. The low,middle and high concentration benzene exposure group＇s rats were respectively breathed in 5 mg/m^3,10 mg/m^3 and 15 mg/m^3 benzene vapor at 1st to 35th day,2hr/day.Control group＇ s rats breathed in air of cabinet at 1st to 35th day,2hr/day.Animals were sacrificed at 36th day to detect the male and female rats＇ indicators of reproductive toxicity. Results The organ coefficient of testis and epididymis and ovarian organ coefficient in medium and high concentration benzene group was significantly lower than that of control group and female rats（P0.05）.The number of sperm in the low, medium and high concentration benzene group was significantly lower compared with control（P0.05）,respectively,16. 23,15.61 and 14.05（×10~7/epididymis）.The sperm motility decreased and sperm deformily increased compared with the control,and the difference had statistical significance（P0.05）.In the middle and high concentration benzene group,the content of male rats＇ serum testosterone was lower than that of the control（P0.05）,and the content of female rats＇ serum FSH,LH and E2 decreased compared with the control（P0.05）.The testicular histopathology in all benzene groups showed：the seminiferous tubules had irregular morphology and unclear border,spermatocyte,primary spermatocyte and secondary spermatocyte didn＇ t arrange closely from the outer to the inner,moreover their shape and structure were damaged in convoluted seminiferous tubule.The convoluted seminiferous tubule was deviated from the center,even it was lacking, only parts of seminiferous tubules contained some mature sperm cells,and with the increasing of benzene concentration,the pathological damage was more obvious.Conclusions 10～15 mg/m^3 benzene exposured by respiratory tiact can lead to male and female rats＇ reproductive system damage.