氟对鸡甲状腺组织结构的影响

Effects of fluoride on thyroid structure in chicks

目的 探讨氟对鸡甲状腺组织结构的影响。方法 选用 2 5 0只 1日龄蛋鸡 ,随机分为 5组 ,每组 5 0只 ,饲喂相同的全价日粮。第 1组为对照组 ,第 2 ,3,4,5组在日粮中添加不同水平的氟化钠 ,使日粮中氟含量分别为 5 0 0 ,10 0 0 ,15 0 0 ,2 0 0 0 mg/kg,实验期 15 0 d。每 30 d采集 1次样品 ,测定血清中氟含量 ,制作甲状腺组织切片 ,称量甲状腺重量 ,观察鸡的临床表现。结果 成功地复制出了不同程度的鸡慢性氟中毒模型。在早期 ,各氟中毒组鸡甲状腺的相对重量均不同程度地低于对照组 ,甲状腺滤泡面积减小 ,胶质减少。中后期 ,则均不同程度地高于对照组 ,滤泡直径和面积增大 ,胶质过度充盈 ,并出现由滤泡旁细胞组成的增生性结节。结论 氟化物对甲状腺的组织结构产生了严重的破坏作用 ,在早期引起鸡甲状腺萎缩 ,中后期则致甲状腺呈胶质性、结节性肿大。

Objective To investigate the effects of fluoride on thyroid structure in chicks.Methods 250 one day chicks were randomly divided into 5 groups , 50 for each .Group I was the control ,and other four groups ,groupⅡ,Ⅲ,Ⅳ,Ⅴ were fed the diets containing 500,1 000,1 500,2 000 mg/kg of fluorine as sodium fluoride, respectively, for 150 days. The contents of serum fluorine were determined, thyroid tissue slices were made , the weight of thyroids was weighed ,and the clinical manifestations of experimental chicks were observed.Results The animal models of chick fluorosis were successfully established.Compared with the control, the earlier changes of thyroid structure were that the relative weight of thyroid and thyroid follicle colloid in all NaF ingestion groups were less, and the size of thyroid follicles was smaller.During the later stage , the results just reversed to the earlier changes , i.e , both areas and diameters of thyroid follicle were larger and the colloid was over filled , and the follicular epithelia were obviously flatted in the enlarged follicles for being crushed by over filling colloid. Moreover, hyperplastic nodules , consisting of thyroid parafollicular cells appeared in group V.Conclusions Fluoride can seriously damage thyroid structure . During the earlier stage , fluoride can induce thyroid atrophia , however, during the later stage ,it can induce thyroid enlargement which is nodular and colloid goiter.