[目的]研究氯丹对大鼠甲状腺结构和功能影响的量效关系研究。[方法]21日龄SD大鼠40只,经7d适应性饲养后,将大鼠随机分为溶剂对照组、低剂量组、中剂量组和高剂量组。每组10只,雌雄各半。低、中、高剂量组的剂量分别为5mg/kg、15mg/kg、30mg/kg,配成相应的玉米油溶液,按0.5%体重灌胃,对照组用同样体积的玉米油灌胃。染毒10d后观察其血清学、组织病理学、组织化学指标和甲状腺滤泡细胞超微结构改变。[结果]随着氯丹染毒剂量的增加,血清FT4、FT3浓度呈逐渐降低的趋势,而TSH浓度则随染毒剂量的增加呈逐渐升高的趋势;甲状腺组织增生的程度随氯丹染毒剂量增加也有明显的加重;PCNA阳性细胞数在实验组明显高于对照组,且随着染毒剂量的增加而增加;各实验组的TPO、SDH酶活性明显升高,表现为显色加深;电镜观察可见实验组的甲状腺滤泡细胞胞浆内有大量明显扩张呈囊状的粗面内质网,胞核、胞膜和线粒体未见损伤。[结论]在一定剂量条件下,氯丹可干扰甲状腺结构和功能,并存在着剂量效应关系。 [Objective] To study the dose-effect relationship of chlordane on the structure and function of thyroid in rats. [Methods] Forty SD rats aged 21 days were randomly divided into control group, low dose group, middle dose group and high dose group after 7d adaptive feeding. Each group of 10, male and female half. The doses of low, medium and high dose groups were 5mg / kg, 15mg / kg and 30mg / kg respectively. The corresponding corn oil solution was dosed by 0.5% body weight. The control group was fed with the same volume of corn oil. After 10 days of exposure, the serological, histopathological, histochemical and ultrastructural changes of thyroid follicular cells were observed. [Results] With the increase of the dose of chlordane, the concentrations of FT4 and FT3 in serum gradually decreased, while the concentration of TSH increased gradually with the increase of the dosage of thyroid. The degree of thyroid tissue hyperplasia The amount of PCNA positive cells in the experimental group was significantly higher than that in the control group, and with the dose increased; the experimental group TPO, SDH activity was significantly increased, the performance of the deepened color Electron microscopy showed that in the cytoplasm of the thyroid follicular cells in the experimental group, there were a large number of rough endoplasmic reticulum with cystic dilatation, and no damage was found in the nuclei, membrane and mitochondria. [Conclusion] Chlordane interferes with the structure and function of thyroid gland at a certain dosage, and there is a dose-response relationship.