不同碘营养状态对老年大鼠甲状腺病理改变的影响

Effect of different iodine nutrition status on the pathological changes of thyroid in aged rats

目的研究不同碘营养状态下老年大鼠甲状腺的病理改变的影响。方法选择20只20月龄正常Wistar大鼠,随机分成对照组(NC组)和高碘组(HI组)。选择20只20月龄低碘甲状腺功能低下模型Wistar大鼠24只,随机分成低碘模型组(LI组)和低碘恢复组(LI-AI组),进行相应碘浓度饲养后检测四组大鼠甲状腺组织重量、三碘甲腺原氨酸(T3)、四碘甲状腺原氨酸(T4)和促甲状腺素(TSH)水平,同时检测甲状腺微粒体抗体(TMAb)和甲状腺球蛋白抗体(TGAb)水平,切片染色观察各组大鼠甲状腺组织的病理改变及CD4+淋巴细胞浸润情况。结果高碘和低碘营养状态均可造成老年大鼠的甲状腺肿大现象,降低其血清中四碘甲状腺原氨酸和三碘甲腺原氨酸水平,提高促甲状腺素(TSH)水平及TMAb、TGAb水平。高碘引起老年大鼠甲状腺滤泡结构破坏,而低碘主要造成滤泡上皮细胞增生。高碘和低碘均可造成滤泡大小改变及严重的CD4+T淋巴细胞浸润。对低碘大鼠进行适量补充碘可以缓解低碘造成的甲状腺肿大、甲状腺内激素改变、甲状腺自有抗体水平、组织损伤和CD4+淋巴细胞浸润情况。结论不同碘营养状态对老年大鼠甲状腺的病理改变具有重要作用。

Objective To observe the effect of different iodine nutrition status on the pathological changes of thyroid in aged rats . Methods 20 Wistar rats aged 20 month were divided into control group ( NC) and high iodine group ( HI) .20 low iodine thyroid function rats aged 20 month were divided into low iodine group ( LI) and low iodine with recovery iodine diet ( LI-AI) .There were feeding with corre-lated iodine for 4 months.Then the weight of thyroid was detected .The level of three iodine thyroid original ammonia acid (T3),four iodine thyroid original ammonia acid (T4) and thyroid stimulating hormone (TSH),and the level of thyroid microsomal antibodies (TMAb) and thyroglobulin antibody ( TGAb) were all detected .The pathological changes of thyroid tissues and CD 4+lymphocyte infiltration of rats were observed by slice staining .Results High iodine and low iodine nutritional status induced thyroid enlargement in aged rat ,reduced the level of serum iodine thyronine and three iodine thyroid original ammonia acid ,improved TSH levels and TMAb ,TGAb levels.High iodine induced structural damage of thyroid follicular structure in aged rats ,while low iodine main caused follicular epithelial cells proliferation .Both high io-dine and low iodine resulted in changes of follicular size and severe CD 4+lymphocyte infiltration .Low iodine rats feed with appropriate iodine could release the changes caused by low iodine in goiter ,thyroid hormones ,thyroid own antibody level ,tissue injury and CD4+lymphocyte in-filtration.Conclusions The different iodine nutrition status has important effect on the pathological changes of thyroid in aged rats .