乙酰基亚硝基脲对C57BL/6J雄鼠毒性作用的研究

目的 观察乙酰基亚硝基脲（ENU）对C57BL/6J雄鼠的毒性作用及对睾丸等组织器官的影响,分析引起小鼠死亡的原因,探索ENU处理雄鼠的最佳处理浓度.方法 将8～10周龄的C57BL/6J 雄鼠分为实验组和对照组.实验组又分为A、B、C、D 4组,分别腹腔注射ENU 150、100、75、50 mg/kg,每周1次,共3次.对照组腹腔注射生理盐水.首次注射ENU后的第1周至12周,每周分别取实验组和对照组小鼠2 只进行剖检并行组织病理学观察,取其睾丸、附睾称重,记录死亡小鼠数量.结果 实验组小鼠剖检发现胸腔纵隔内有巨大肿块,明显压迫心脏;组织切片观察发现睾丸和肝、肾有不同程度的病理改变.结论 ENU为小鼠的一种强诱变剂,纵隔肿瘤是导致雄鼠死亡的主要原因,ENU对睾丸的毒性作用最强,主要表现为曲精小管组织结构破坏,生精细胞减少.ENU处理雄鼠的最佳浓度为150 mg/kg.

Study of the toxicity of ENU on male C57BL/6J mice

Objective To investigate the toxicity of N - ethyl - N - nitrosourea （ENU） on male C57BL/6J mice as well as the effect on the testes and other organs, and to analyze the cause of death of mice so as to explore the optimal concentration of ENU in the treatment of male mice. Methods Male C57BL/6J mice aged about 8 to 10 weeks were divided into experimental and control groups. The experimental groups were further divided into four （A, B, C and D） groups and were intraperitoneally injected with different doses of ENU （ 150 mg/kg, 100 mg/kg, 75 mg/kg and 50 mg/kg, respectively） once a week for 3 times, while the control group underwent injection of normal saline. From the first week to the twelfth week after the initial injection of ENU, 2 mice from the experimental group and 2 mice from the control group were sacrificed for autopsy and histopathological observation per week, and the testes and epididymides were weighed, and mice deaths were recorded. Results Autopsy revealed a big tumor within the mediastinum in the chest, which evidently suppressed the heart; observation of histological sections showed different pathological changes in the testes, the liver and kidneys. Conclusion ENU is a strong mutagen to mice, mediastinal tumor is the primary cause leading to mouse death. ENU has the strongest testicular toxicity, mainly presented as the seminiferous tubule destruction and the spermatogenic cells reduction. The optimal concentration of ENU in the male mouse should be 150 mg/kg.