过氯酸铵对大鼠碘负荷及抗氧化能力的影响

发布时间：2018-03-07 06:09

本文选题：过氯酸铵　切入点：甲状腺　出处：《华中科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的过氯酸铵（Ammonium Perchlorate，AP）是一种白色晶体粉末，是导弹和火箭复合固体推进剂的重要组分，被广泛应用于航天航空工业和国防工业。AP在生产和使用中会散出大量的粉尘，通过不同的途径进入机体产生健康损害。已有研究发现AP可致甲状腺结构发生改变，并影响其正常功能。本实验室曾有研究发现AP可影响大鼠甲状腺激素的分泌以及钠碘转运体的表达。本实验旨在探讨过氯酸铵对大鼠体内碘负荷和抗氧化能力的影响，阐述其毒作用机制，为预防和控制过氯酸铵对职业人群的健康危害、保护工人健康提供科学依据。方法将SD雄性大鼠20只随机分成4组，即对照组、AP低剂量组、中剂量组和高剂量组，每组5只。染毒剂量分别为0、130、260、520mg·kg~(-1)·d~(-1)，，经口饮水染毒。每周定时称量体重1次，并依据体重计算AP染毒量，持续染毒13周。于染毒第6周和第13周时，分别采用挤压膀胱反射排尿法采集大鼠尿液，用尿碘砷铈催化分光光度法检测大鼠尿碘水平。染毒13周后处死并解剖大鼠，取甲状腺、心、肝、脾、肺、肾及睾丸，分别称重，并计算脏器系数。取部分甲状腺组织，采用食物中碘的测定法检测甲状腺组织总碘量、相对含碘量。取部分甲状腺组织匀浆,试剂盒检测蛋白定量、丙二醛（MDA）、超氧化物歧化酶（SOD）、甲状腺过氧化氢酶（CAT）等指标。结果大鼠经AP染毒至13周，高、中剂量组大鼠的体重增长明显低于对照组，差异有统计学意义（P0.05）；各剂量组的甲状腺脏器系数均显著高于对照组，差异有统计学意义（P0.01）；染毒第6周AP高剂量组尿碘水平比对照组明显升高（P0.05），而染毒第13周各剂量组尿碘水平与对照组比较均无明显差别（P0.05）。染毒至第13周，各剂量组甲状腺总碘量均明显低于对照组，差异有统计学意义（P0.01）；各剂量组相对含碘量明显低于对照组，并随染毒剂量的升高而逐渐下降，差异有统计学意义（P0.01）；AP染毒各剂量组甲状腺总蛋白定量水平与对照组相比均有下降，但仅中、高剂量组差异具有统计学意义（P0.05）；各剂量组MDA含量与对照组比较均无明显差异（P0.05）；而各剂量组SOD活力与对照组相比均有升高，但其差异尚不显著（P0.05）；AP低、中、高剂量组大鼠CAT活力与对照组相比，呈逐渐升高趋势，但只有高剂量组与对照组相比具有统计学意义（P0.01）。结论本研究通过AP染毒大鼠13周表明，AP对大鼠具有毒作用，其靶器官为甲状腺。AP可竞争性抑制甲状腺摄取碘，使甲状腺摄碘不足，在一定时间内表现为大鼠尿碘增加，并致甲状腺组织含碘量降低，进而导致甲状腺组织代偿性增生肿大和体重增长迟缓。另外，AP可致甲状腺蛋白定量水平减少，并对甲状腺组织造成氧化损伤，引起甲状腺过氧化氢酶活性升高。以上结果均表明，AP对甲状腺具有明显的毒作用，为进一步阐明AP对健康的危害提供了可靠的实验依据。
[Abstract]:Objective Ammonium Perchlorate APs is a kind of white crystal powder, which is an important component of missile and rocket composite solid propellant. It is widely used in aerospace industry and national defense industry. Health damage is caused by entering the body in different ways. It has been found that AP can cause changes in thyroid structure. It has been found that AP can affect the secretion of thyroid hormone and the expression of sodium iodide transporter in rats. The aim of this study was to investigate the effects of ammonium perchlorate on iodine load and antioxidant capacity in rats. The mechanism of toxic effect of ammonium perchlorate is described in order to provide scientific basis for preventing and controlling the health hazard of ammonium perchlorate to occupational population and protecting the health of workers. Methods Twenty Sprague-Dawley male rats were randomly divided into 4 groups: control group with low dose of AP, medium dose group and high dose group with 5 rats in each group. The dosage of AP was calculated according to body weight for 13 weeks. At the 6th and 13th weeks of exposure, the urine of rats was collected by pressing bladder reflex urination method. Urinary iodine level was determined by catalytic spectrophotometry. After 13 weeks of exposure, rats were killed and dissected. Thyroid gland, heart, liver, spleen, lung, kidney and testis were weighed, and organ coefficients were calculated. The total iodine content and relative iodine content of thyroid tissue were determined by the method of determination of iodine in food. Some thyroid tissue homogenate was taken, the protein quantity was detected by kit, malondialdehyde (MDA) MDAA, superoxide dismutase (SOD) and catalase (CAT) were measured. Results the weight gain of rats in the middle dose group was significantly lower than that in the control group (P 0.05), and the thyroid organ coefficient of each dose group was significantly higher than that of the control group, the rats were exposed to AP for 13 weeks, and the weight gain in the middle dose group was significantly lower than that in the control group (P 0.05). The level of urinary iodine in the AP high dose group was significantly higher than that in the control group at the 6th week of exposure, but there was no significant difference in urinary iodine level between the control group and the control group at the 13th week after exposure, and the level of urinary iodine in the AP high dose group was not significantly different from that in the control group from the 13th week to the 13th week. The total iodine content of thyroid in each dose group was significantly lower than that in the control group, the difference was statistically significant (P 0.01), the relative iodine content in each dose group was significantly lower than that in the control group, and gradually decreased with the increase of the dose. The difference was statistically significant (P 0.01). The quantitative level of thyroid total protein in each dose group was lower than that in the control group, but it was only moderate. There was no significant difference in the content of MDA between the high dose group and the control group (P 0.05), but the activity of SOD in each dose group was higher than that in the control group, but the difference was not significant (P 0.05), but the difference was not significant (P 0.05). Compared with the control group, the activity of CAT in the high dose group was gradually increased, but only in the high dose group compared with the control group, there was a statistically significant difference between the high dose group and the control group (P 0.01). Conclusion in this study, the rats exposed to AP for 13 weeks showed that AP had toxic effect on rats. The target organ of AP was thyroid. AP could competitively inhibit thyroid uptake of iodine, which resulted in insufficient uptake of iodine by thyroid, and increased urinary iodine in rats in a certain period of time. The iodine content of thyroid tissue was decreased, which resulted in compensatory hyperplasia of thyroid tissue and slow weight gain. AP also decreased the quantitative level of thyroid protein and caused oxidative damage to thyroid tissue. The above results indicate that AP has obvious toxic effect on thyroid gland, which provides a reliable experimental basis for further elucidating the harm of AP to health.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R114

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