摘要
目的 建立大鼠高碘低蛋白动物模型,观察高碘低蛋白对大鼠生长代谢的影响及甲状腺的病理形态学变化.方法 192只断乳1个月Wistar大鼠,雌雄各半,按体质量[（110±10）g]及性别采用随机数字表法分为①对照组（NI）：正常饲料＋自来水;②正常饲料＋ 10倍碘组（10HI）;③正常饲料＋50倍碘组（50HI）;④正常饲料＋ 100倍碘组（100HI）;⑤低蛋白对照组（LC）：低蛋白饲料＋自来水;;⑥低蛋白饲料＋10倍碘组（L10HI）;⑦低蛋白饲料＋ 50倍碘组（L50HI）;⑧低蛋白饲料＋100倍碘组（L100HI）.每组24只大鼠.NI、LC组大鼠每日摄碘量为4.65 μg/d,10倍、50倍、100倍碘组大鼠每日摄碘量分别为46.50、232.50、465.00μg/d.实验期为6个月,每周称大鼠体质量、记录饮水及饲料消耗情况;分别于实验第60、120、180天,每组取8只大鼠,收集尿液,砷铈催化分光光度法检测尿碘,并取血清,氯酸法检测血清碘.实验终末,取各组大鼠甲状腺组织,HE染色及透射电子显微镜观察病理及超微结构变化情况;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）法检测甲状腺细胞凋亡情况.结果 实验第4、8、16、18、22、24周时,各组大鼠体质量组间比较差异有统计学意义（F值分别4.26、3.75、4.98、4.09、3.28、3.95,P均＜0.05）.实验第60、120、180天时,各组大鼠尿碘、血清碘组间比较差异有统计学意义（H值分别为5.37、6.03,P均＜0.05）.HE染色后光镜下观察,各组大鼠随着碘含量的增加甲状腺滤泡增大、上皮细胞呈扁平状、滤泡腔内充满丰富浓染胶质.透射电镜观察,各组大鼠随着碘含量的增加甲状腺滤泡上皮细胞内胶质小泡增多、内质网线粒体出现空泡样变、染色质浓缩、核膜不完整、核碎裂.各组大鼠甲状腺细胞凋亡指数组间比较差异有统计学意义（F=4.59,P＜0.01）,其中L50HI、L100HI组[（21.50±5.20）‰、（26.70±6.40）‰]分别高于50HI、100HI组[（11.20±4.30）‰、（19.40±4.80）‰,P＜ 0.01或＜ 0.05].结论 高碘低蛋白可导致大鼠体格发育迟滞,碘代谢异常,并对甲状腺滤泡上皮细胞造成损伤.
Objective To establish an animal model of high-iodine and low-protein in Wistar rats,and to observe the effect of combined excess-iodine and low-protein diet on growth,metabolism and morphological changes in thyroid.Methods According to body weight[（110 ± 10）g] and sex（half male and half female）,one hundred and ninety-two Wistar rats,1 month after weaning,were randomly divided into ① normal iodine control group （NI）,② 10-fold excess-iodine group （10HI）,③ 50-fold excess-iodine group （50HI）,④ 100-fold excess-iodine group （100HI）,⑤ low-protein control group （LC）,⑥ low-protein and l 0-fold excess-iodine group （L10HI）,⑦low-protein and 50-fold excess-iodine group （L50HI）,⑧ low-protein and 100-fold excess-iodine group（L100HI）.Twenty-four rats were in each group,with the experimental period of 6 months.The iodine content of NI and LC groups was 4.65 μg/d; 10HI,50HI and 100HI groups were 46.50,232.50 and 465.00 μg/d,respectively.The animal＆#39;s body weight,water and feed consumption were recorded weekly.At the end of 60,120,180 days,urine and blood samples were collected from eight rats in each group.Urinary iodine was tested by arseni cerium catalytic spectrophotometry; serum iodine was tested by the method of chloric acid.Histological change of the thyroid gland was observed by transmission electron microscopy and hematoxylin-eosin （HE） staining at the end of 6 months; apoptosis of thyroid was tested by terminal-deoxynucleoitidyl transferase mediated nick end labeling （TUNEL） method.Results At the end of 4,8,16,18,22 and 24 weeks,the differences of body mass of rats among groups were statistically significant（F =4.26,3.75,4.98,4.09,3.28,3.95,all P 〈 0.05）.At the end of 60,120,180 days,the differences of iodine concentration in urine and blood among groups were statistically significantly （H =5.37,6.03,all P 〈 0.05）.Light microscopy showed that thyroid follicular epithelial cells became flattened,and follicles became distended with colloid following increasing of iodine concentration.Electron microscopy showed increased glial vesicles,condensation of nuclear chromatin,karyopyknosis,and karyolysis with increasing of iodine concentration.The differences of apoptotic indexes among groups were statistically significant （F =4.59,P 〈 0.01）.The apoptotic indexes of L50HI and L100HI groups [（21.50 ± 5.20）‰,（26.70 ± 6.40）‰] were higher than those of 50HI and 100HI groups [（11.20 ± 4.30）‰,（19.40 ± 4.80）‰,P 〈 0.01 or 〈 0.05].Conclusion Excessiodine and low-protein can cause growth retardation,abnormal iodine metabolism,and thyroid follicular epithelium damage in Wistar rats.
出处
《中华地方病学杂志》
CAS
CSCD
北大核心
2014年第5期511-516,共6页
Chinese Journal of Endemiology
基金
国家自然科学基金（30772134）
