摘要
目的探讨中、轻度碘过量对碘缺乏和非碘缺乏Wistar大鼠甲状腺滤泡上皮细胞凋亡及Fas/FasL表达的影响。方法碘缺乏大鼠以饲过氯酸钾制备饲料,随机分成3个组,补碘量分别为0、840、1680μg/L。非碘缺乏大鼠随机分成补碘量分别为0、280、560、840、1680、2800和5600μg/L组。脱氧核糖核苷酸末端转移酶介导原位缺口末端标记(TUNEL)确定细胞凋亡数。免疫组化和原位杂交法观察Fas/FasL表达。结果①碘缺乏大鼠:与补碘0μg/L组相比,饮水碘840μg/L组7d和90d时Fas表达明显降低,P分别<0.01和0.001。FasL的表达也下降,但差异无统计学意义。细胞凋亡数在补碘21d和90d有显著降低,P均<0.05。补碘90d时Fas鄄mRNA和FasL鄄mRNA表达明显低于0μg/L组,P<0.001。②非碘缺乏大鼠:补碘90d时,840、1680、2800、5600μg/L组Fas和FasL表达明显高于280和560μg/L组,P<0.001。840、2800和5600μg/L补碘组细胞凋亡数明显高于280和560μg/L组,P<0.001。补碘组Fas鄄mRNA表达明显高于碘0μg/L组,P<0.001,FasL鄄mRNA表达与0μg/L组相比差异无统计学意义。结论过量碘(尿碘中位数>300μg/L)补碘90d,使碘缺乏机体甲状腺滤泡上皮细胞凋亡数和Fas表达明显减少,非碘缺乏机体甲状腺滤泡上皮细胞凋亡数、Fas和FasL的表达均明显增加。
Objective To study the effects of mild and moderate iodine ex cess on apoptosis and expressions of Fas and FasL in thyroid follicular epitheli umin in iodine-deficient and non-iodine-deficient Wistar rats. Methods Iodine deficient rats made up by excess intake of potassium perchlorate were randomly fed with double distilled water (DDW) with 0, 840 or 1 680 μg/L iodine load, re spectively. Non-iodine-deficient rats drank DDW with 0, 280,560,840,1 680, 2 800 or 5 600 μg/L iodine load, respectively. Expressions of Fas/FasL were determin ed by SP immunohistochemistry and in situ hybridization. TUNEL(Transferase media ted dUTP nick end labeling) was used to determine apoptosis. Results ①In iodi ne-deficiency rats, the expression of Fas was markedly lower than the group drin king 0 μg/L iodine after drinking DDW with 840 μg/L iodine for 7 days and 90 d ays, P < 0.01 and 0.001 respectively. The expression of FasL was gradually reduc ed but without significant difference when compared with 0 μg/L iodine water gr oup. The number of apoptotic thyrocytes was also gradually reduced and significa nt difference was seen after drinking DDW with 840 μg/L iodine for 21 days and 90 days, both P < 0.05. The expressions of Fas-mRNA and FasL-mRNA in iodine exce ss groups were significantly lower than 0 μg/L iodine group, both P < 0.001. ② In non-iodine-deficiency rats, 90 days after treatment, the expressions of Fas a nd FasL in the groups with iodine load of 840, 1 680,2 800,5 600 μg/L iodine we re markedly higher than those in groups with iodine load of 280 and 560 μg/L. T he number of apoptotic thyrocytes in the groups with iodine concentration of 840 , 2 800 and 5 600 μg/L were markedly higher than those in groups of 280 and 560 μg/L iodine, P < 0.001. The expression of Fas-mRNA in iodine excess groups was higher than those in 0 μg/L iodine group, P < 0.001. The expression of FasL-mR NA in iodine excess group was not significantly different when compared with 0 μg/L iodine water group. Conclusions Excessive iodine intake(Median urinary iodine, > 300 μg/L) for 90 days, markedly decreases the number of apoptotic thy rocytes and expression of Fas in iodine-deficient rats while markedly increases the number of apoptotic thyrocytes and the expressions of Fas and FasL in non-io dine-deficiency rats.
出处
《中国地方病学杂志》
CAS
CSCD
北大核心
2005年第3期267-270,共4页
Chinese Jouranl of Endemiology
基金
国家自然科学基金资助项目(39970350)
