【作者】 李研超；

【导师】 张迎梅；

【作者基本信息】 兰州大学 ， 动物学， 2008， 硕士

【摘要】 近年来,环境中的人造化学物质影响机体内分泌功能并进而引发各类疾病的问题日益引起人们的关注。在环境内分泌干扰物(EDs)中,农药是所占比例最大的一类。除草剂阿特拉津作为一种具有代表性的农药类内分泌干扰物,其在全球范围内的广泛使用对生态平衡和人类健康造成了巨大危害。本文以发育期SD大鼠为实验对象,采用慢性经口染毒的方法,通过测定免疫器官脏器指数、外周血T淋巴细胞转化率、半数血清溶血素三项指标,研究了阿特拉津对发育期SD大鼠免疫功能的影响并初步探讨了其免疫毒性作用机理。实验结果显示,低剂量(25mg/kg)阿特拉津对SD大鼠免疫器官重量和细胞免疫应答能力无显著影响,但可使雌性大鼠的体液免疫能力明显上升。中剂量(125mg/kg)阿特拉津染毒可使雄性大鼠胸腺明显萎缩(P＜0.05),使雌、雄大鼠的细胞免疫和体液免疫应答水平均明显下降(P＜0.05 or P＜0.01)。高剂量(250mg/kg)阿特拉津处理对SD大鼠免疫系统及其功能的损伤更加显著,雌性和雄性大鼠的胸腺均严重萎缩,其中雄鼠胸腺指数的降低更加明显(P＜0.01),大鼠细胞免疫和体液免疫应答能力进一步降低(P＜0.01)。整个实验期间,雄鼠对阿特拉津的毒性作用显示出比雌鼠更高的敏感性,同时各剂量组大鼠的脾脏指数均无显著降低,显示阿特拉津对中枢免疫器官胸腺比外周免疫器官脾脏具有更强的损伤作用。综上所述,阿特拉津对发育期SD大鼠具有免疫毒性,对雄性的损伤强于雌性,其毒性作用随染毒剂量升高而增强。阿特拉津通过损伤胸腺,降低细胞免疫和体液免疫能力,从而抑制机体免疫功能,导致癌症等疾病的高发。更多还原

【Abstract】 In recent years, the issue that man-made chemicals in environment could affect the immune function of organisms and arouse many diseases has increasingly attracted the public attention. Among Endocrine Disruptors (EDs), the pesticide possesses the most proportion. The herbicide atrazine is a typical endocrine disrupting pesticide, it is widely used in all over the world, and brings huge damage to the ecological balance and human health. In this paper, the developing SD rat was adopted as test animal, and the effect of atrazine on immune system was studied by observing the index of thymus and spleen, the T lymphocyte transformation and the hemolysin in chronically oral exposure tests. The immunotoxic mechanism of atrazine was also primarily discussed.The result of experiment indicated that the low dose (25mg/kg) atrazine wouldn’t obviously affect the immune organ’s index and the cell-medicated immunoresponse of SD rat, but would make the humoral immunity level of female SD rat rise largely. The medium dose (125mg/kg) atrazine would make the male rat’s thymus atrophy (P< 0.05) and make the cell-medicated and the humoral immunoresponses fall obviously (P<0.05 or P<0.01). The high dose (250mg/kg) atrazine would damage the immune system and its function of SD rat more seriously. In this group, the thymus of both male and female rat badly atrophied, and the thymus index of male rat fell more obviously (P < 0.01). The ability of the cell-medicated and the humoral immunoresponses of SD rat also fell worse. During the whole experiment, the male rat seemed to be more sensitive to the toxicity of atrazine than the female. The spleen index of each group also didn’t fall a lot, what indicated that the atrazine would injure the thymus more than the spleen.In one word, atrazine has immunotoxicity in developing SD rat, its toxic effect will be more obviously with rise of the dose, and the male will be more sensitive to it than the female. Atrazine restrains the immunoability through injuring the thymus and reducing the level of the cell-medicated and the humoral immunoresponses, and leads to the incidence of diseases such as cancer rising largely.更多还原