无机砷暴露对SD大鼠外周血甲状腺激素水平的影响研究

Effects of Inorganic Arsenic Exposure on Thyroid Hormone Levels in Peripheral Blood of SD Rats

目的:探讨不同浓度无机砷暴露对SD大鼠外周血甲状腺激素水平的影响,为进一步研究砷致甲状腺损伤及其机制提供基础数据。方法:健康初断乳SD大鼠24只,雌雄各半,适应性饲养一周后随机分为正常对照组、低砷剂量组、中砷剂量组、高砷剂量组,每组6只。正常对照组给予去离子水灌胃,低、中、高砷剂量组按体重分别给予2.5 mg/kg、5.0 mg/kg、10.0 mg/kg亚砷酸钠(NaAsO_(2))水溶液灌胃,每周6天,连续36周。到达染毒终点麻醉大鼠,心脏采集非抗凝血并分离血清,采用酶联免疫吸附法检测各组大鼠血清中总三碘甲状腺原氨酸(TT_(3))、游离T_(3)(FT_(3))、总甲状腺素(TT_(4))、游离T_(4)(TT_(4))水平。结果:长期无机砷暴露可导致SD大鼠饮水进食量减少并出现异常行为,且其体重较对照组大鼠明显降低(P<0.05);NaAsO_(2)染毒36周后,SD大鼠血清TT_(3)、FT_(3)、TT_(4)、FT_(4)水平显著低于对照组(P<0.05),且呈一定的剂量依赖性。结论:长期无机砷暴露可导致SD大鼠外周血甲状腺激素水平降低,影响甲状腺功能。

Objective:To investigate the effects of different concentrations of inorganic arsenic exposure on thyroid hormone levels in peripheral blood of SD rats,so as to provide basic data for further research on arsenic-induced thyroid injury.Methods:Twenty-four healthy SD rats(half male and half female)are randomly divided into normal control group,low arsenic dose group,medium arsenic dose group and high arsenic dose group after adaptive feeding for a week,with 6 rats in each group.The normal control group is given deionized water by gavage,and the low,medium and high arsenic groups are given 2.5 mg/kg,5.0 mg/kg and 10.0 mg/kg sodium arsenite(NaAsO_(2))solution by gavage according to body weight,6 days a week for 36 weeks.Non-anticoagulant blood is collected from the heart and serum is isolated.The serum levels of total triiodothyronine(TT_(3)),free T_(3)(FT_(3)),total thyroxine(TT_(4))and free T_(4)(TT_(4))are detected by enzyme-linked immunosorbent assay.Results:Long-term exposure to inorganic arsenic can lead to decreased water and food intake,abnormal behavior in SD rats,and the body weight of SD rats is significantly lower than that of control rats(P<0.05);After 36 weeks of NaAsO_(2) exposure,the serum TT_(3),FT_(3),TT_(4),FT_(4) levels of SD rats are significantly lower than that of control rats(P<0.05),and it is dose-dependent.Conclusion:Long-term exposure to inorganic arsenic can reduce thyroid hormone levels in peripheral blood of SD rats and affect thyroid function.