Cui Y S, Zhong Q, Li W F, Liu Z H, Wang Y, Hou C C
Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2017 Dec 20;35(12):888-892. doi: 10.3760/cma.j.issn.1001-9391.2017.12.002.
To investigate the effects of fluoride exposure on the thyroid hormone level and intelligence in rats and to investigate the biomarkers of intellectual impairment induced by high fluoride exposure. A total of 24 clean healthy Sprague-Dawley rats were randomly divided into control group (tap water containing 0.344 mg/L fluoride) and low-, medium-, and high-fluoride exposure groups (tap waters containing 10, 50, and 100 mg/L sodium fluoride, respectively). One male rat was cohabited with two female rats in the same group. After the offspring rats were weaned, 12 offspring rats (male/female ratio=1∶1) with a similar body weight in each group were subjected to the same treatment for the parental offspring. The offspring rats were sacrificed on the 60th day after birth. The weight of offspring rats was measured. Serum thyrotropin (TSH) , free triiodothyronine (FT(3)) , and free thyroxine (FT(4)) levels were measured by enzyme-linked immunosorbent assay. The learning and memory abilities of the rats were evaluated by Morris water maze test. The expression of mitochondrial fission 1 (Fis1) and mitofusin 1 (Mfn1) in blood was measured by Western blot. The offspring rats in the medium-and high-fluoride exposure groups had significantly lower serum TSH and FT(4) levels than those in the control group (<0.05). The place navigation test showed that the offspring rats in the medium-and high-fluoride exposure groups had significantly longer escape latency than those in the control group (<0.05) , and the high-fluoride exposure group had a significantly longer escape distance than those in the control group (<0.05). The spatial probe test showed that the offspring rats in the low-, medium-, and high-fluoride exposure groups had significantly shorter swimming time and distance in the target quadrant and total swimming time and distance than those in the control group (<0.05). Compared with the offspring rats in the control group, those in the low-, medium-, and high-fluoride exposure groups had significantly higher expression of Fis1 (<0.05) , and those in the low- and medium-fluoride exposure groups had significantly higher expression of Mfn1 (<0.05) . High fluoride exposure can reduce the secretion of thyroid hormone and the abnormality of mitochondrial dynamics in peripheral lymphocytes may provide a clue to identifying the biomarkers of intellectual impairment induced by fluoride exposure.
探讨氟暴露对大鼠甲状腺激素水平和智力的影响，并探究高氟暴露致智力损害的生物标志物。将24只清洁健康的Sprague-Dawley大鼠随机分为对照组（含0.344 mg/L氟的自来水）和低、中、高氟暴露组（分别含10、50和100 mg/L氟化钠的自来水）。每组1只雄鼠与2只雌鼠合笼饲养。子代大鼠断乳后，每组选取12只体重相近的子代大鼠（雄/雌比例 = 1∶1），对其进行与亲代相同的处理。子代大鼠于出生后第60天处死，测量子代大鼠体重。采用酶联免疫吸附测定法检测血清促甲状腺激素（TSH）、游离三碘甲状腺原氨酸（FT(3)）和游离甲状腺素（FT(4)）水平。采用Morris水迷宫试验评估大鼠的学习和记忆能力。采用蛋白质免疫印迹法检测血液中线粒体分裂蛋白1（Fis1）和线粒体融合蛋白1（Mfn1）的表达。中、高氟暴露组子代大鼠血清TSH和FT(4)水平显著低于对照组（<0.05）。定位航行试验显示，中、高氟暴露组子代大鼠逃避潜伏期显著长于对照组（<0.05），高氟暴露组子代大鼠逃避距离显著长于对照组（<0.05）。空间探索试验显示，低、中、高氟暴露组子代大鼠在目标象限的游泳时间和距离、总游泳时间和距离均显著短于对照组（<0.05）。与对照组子代大鼠相比，低、中、高氟暴露组子代大鼠Fis1表达显著升高（<0.05），低、中氟暴露组子代大鼠Mfn1表达显著升高（<0.05）。高氟暴露可降低甲状腺激素分泌，外周淋巴细胞线粒体动力学异常可能为识别氟暴露致智力损害的生物标志物提供线索。
