邻苯二甲酸二(2-乙基)己酯对雌性大鼠甲状腺的毒性作用

Toxicity of di-2-ethylhexyl phthalate to thyroid of female rats

目的探讨邻苯二甲酸二(2-乙基)己酯(DEHP)对雌性大鼠甲状腺的毒性作用。方法 SD雌性大鼠24只,随机分为4组,每组6只。低、中、高剂量染毒组分别每天用50.0、158.2和500.0 mg/kg DEHP连续灌胃染毒4周,阴性对照组每天灌胃给予0.10 ml/kg玉米油。动态观察大鼠的一般情况和体重变化,测定不同浓度DEHP染毒后大鼠血清中三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)及促甲状腺素(TSH)的变化情况及甲状腺组织的病理改变,并测定大鼠血清、甲状腺组织中谷胱甘肽过氧化物酶(GSH-Px)活力和丙二醛(MDA)含量。结果 DEHP染毒对大鼠体重和食物利用率无明显影响。光镜下可见高剂量染毒组甲状腺滤泡体积变小,腔内胶质密度下降。与对照组相比,高剂量染毒组大鼠血清T3水平下降,中、高剂量组血清GSH-Px活力降低,高剂量组甲状腺组织中GSH-Px活力降低,高剂量组血清和甲状腺组织中MDA含量均增加,差异均有统计学意义(P<0.05)。结论 DEHP对大鼠的甲状腺毒性作用可能与氧化应激反应有关。

Objective To explore the toxicity of di-2-ethylhexyl phthalate （DEHP） to female rats. Methods A total of 24 Sprague Dawley female rats were randomly divided into four groups, six rats in each group. The animals were exposed to DEHP at the doses of 50.0, 158.2 and 500.0 mg/kg body weight per day respectively by gavage for four consecutive weeks. The general conditions and body weight of the rats were observed. At the end of the exposure, pathological change of the thyroid tissue was examined and T3, T4, TSH, GSH-Px, and MDA in blood or thyroid tissue were measured. Results In the thyroid, a reduction in the size of follicles and decrease in colloid density were seen in 500.0 mg/kg group. Compared with the control, T3 level significantly decreased in 500.0 mg/kg group, GSH-Px activity in the blood decreased dramatically in both 158.2 and 500.0 mg/kg groups, while in thyroid tissue, it decreased only in the highest dosage group. MDA level increased in both thyroid tissue and blood in the highest dosage group. Conclusion DEHP has toxic effects on thyroid in rats, the oxidative stress injuries may be one of the possible mechanism.