环境内分泌干扰物多氯联苯118对大鼠甲状腺形态及功能影响的研究
发布时间：2019-06-20 10:46
【摘要】：目的:1.构建PCB118持续低浓度损害特点的大鼠甲状腺模型;2.观察PCB118对大鼠甲状腺形态及功能的影响;3.探讨PCB118诱导甲状腺细胞功能障碍的可能机制。方法:1.将PCB118溶于玉米油,配成相应浓度的PCB118玉米油溶液,用于大鼠腹腔注射(给药容积0.5m L/kg)。选取40只清洁级健康成年雄性Wistar大鼠,体重(200±10)g,按PCB118给予剂量随机分为溶剂对照组(0μg/kg/d)、低剂量组(10μg/kg/d)、中剂量组(100μg/kg/d)、高剂量组(1000μg/kg/d)4组,每组各10只,每周连续给药5天(每天1次),每日称重后绘制大鼠周龄体重生长曲线,造模13周后心脏采血处死,立即取出甲状腺组织,按实验要求分别保存。血样经4℃离心后分离血清,按需分装后于-70℃冻存。2.取大鼠一侧甲状腺组织经4%多聚甲醛固定后石蜡包埋,连续切片后进行HE染色,光镜下观察甲状腺病理结构变化并拍照。3.取1mm3大小甲状腺组织,用5%戊二醛-1%锇酸双重固定,经块染、脱水、浸渍、包埋、聚合后,超薄切片,透射电镜下观察大鼠甲状腺超微结构变化并拍照。4.采用放射性免疫法测定大鼠血清FT3、FT4、TSH、TG、TGAb及TPOAb水平,参照相应RIA分析试剂盒说明书进行。5.提取甲状腺组织总RNA后,RT-q PCR方法检测大鼠甲状腺组织NIS、TG、TPO、AKT、Fox O3a m RNA表达变化。6.提取甲状腺组织总蛋白后,Western blotting方法检测大鼠甲状腺组织AKT、p-AKT及p-Fox O3a蛋白表达变化。结果:1.腹腔PCB118注射给药后,实验组与对照组比较,大鼠行为无明显异常改变,正常摄食、饮水,无明显腹泻。各组间体重无明显差异(P0.05)。2.光镜下对照组大鼠甲状腺滤泡腔完整,为单层立方上皮,腔内充满均匀胶质。各实验组均可见甲状腺组织增生、滤泡扩张、滤泡腔塌陷、上皮脱落、胶质缺失、间质纤维化、小血管增生及纤维素样坏死等,损伤程度随着PCB118剂量的增加而明显加重。3.透射电镜下对照组甲状腺细胞顶端膜微绒毛丰富、胞质中内质网排列整齐、紧密,线粒体嵴清晰可见,形态正常;各实验组甲状腺滤泡上皮细胞核周间隙增加,内质网扩张伴空泡化,线粒体肿胀,部分伴空泡化、线粒体嵴消失、密度下降,损伤程度亦随PCB118剂量的增加而明显加重。4.随着PCB118剂量增加,大鼠血清FT3、FT4、TSH、TG浓度均逐渐降低,高剂量组FT3浓度明显低于对照组和低剂量组(P0.05);各实验组血清FT4、TSH浓度均明显低于对照组(P0.05);中、高剂量组血清TG水平明显低于对照组(P0.05)。与对照组比较,低、中剂量组血清TGAb、TPOAb浓度显著升高(P0.05);5.与对照组比较,甲状腺组织NIS和TG m RNA表达水平在中、高剂量组明显减低(P0.05),但在低剂量组则无明显改变。与低剂量组比较,中、高剂量组TG m RNA明显减低,差异有统计学意义(P0.05)。与对照组比较,中剂量组甲状腺组织TPO m RNA表达水平明显上升(P0.05),高剂量组TPO m RNA表达水平明显低于中剂量组(P0.05)。6.(1)与对照组比较,甲状腺组织AKT m RNA表达水平在高剂量组明显升高(P0.05),但在低、中剂量组则无明显改变。各实验组甲状腺组织Fox O3a m RNA表达水平与对照组比较无明显改变。(2)与对照组比较,甲状腺组织AKT蛋白表达水平在中、高剂量组明显升高(P0.05),但在低剂量组则无明显改变;p-AKT蛋白表达仅在高剂量组明显升高(P0.05);各实验组甲状腺组织p-Fox O3a蛋白表达与对照组比较均明显升高(P0.05)。结论:1.慢性低浓度PCB118持续暴露可造成大鼠甲状腺组织形态结构异常及细胞功能障碍,并存在一定剂量效应关系;2.慢性低浓度PCB118可诱导甲状腺自身免疫反应,导致血清甲状腺自身抗体水平增加;3.慢性低浓度PCB118可引起甲状腺激素重要功能基因NIS及TG m RNA表达减低,亦存在一定剂量效应关系;4.慢性低浓度PCB118可以激活PI3K/AKT通路,促使Fox O3a磷酸化水平增加。
[Abstract]:Objective:1. To construct a rat thyroid model with the characteristics of persistent low-concentration damage of PCB118; The effect of PCB 118 on the thyroid morphology and function of rats was observed. To explore the possible mechanism of PCB118 to induce the dysfunction of thyroid cell. Method:1. The PCB 118 is dissolved in corn oil to prepare a corresponding concentration of the PCB 118 corn oil solution for intraperitoneal injection of the rat (administration volume of 0.5 m L/ kg). 40 healthy adult male Wistar rats, weighing (200 to 10) g, were randomly divided into a solvent control group (0. mu.g/ kg/ day), a low-dose group (10. mu.g/ kg/ day), a medium-dose group (100. mu.g/ kg/ day), a high-dose group (1000. mu.g/ kg/ d) of 4 groups, each group of 10 rats, The body weight growth curve of the rat was drawn daily for 5 days (once a day), and the body weight growth curve of the rat was drawn after daily weighing. After the model was made for 13 weeks, the heart was sacrificed and the thyroid tissue was taken out immediately and stored according to the requirements of the experiment. The blood samples were centrifuged at 4 & deg; C and the serum was isolated and stored at -70 鈩，
本文编号：2503158
[Abstract]:Objective:1. To construct a rat thyroid model with the characteristics of persistent low-concentration damage of PCB118; The effect of PCB 118 on the thyroid morphology and function of rats was observed. To explore the possible mechanism of PCB118 to induce the dysfunction of thyroid cell. Method:1. The PCB 118 is dissolved in corn oil to prepare a corresponding concentration of the PCB 118 corn oil solution for intraperitoneal injection of the rat (administration volume of 0.5 m L/ kg). 40 healthy adult male Wistar rats, weighing (200 to 10) g, were randomly divided into a solvent control group (0. mu.g/ kg/ day), a low-dose group (10. mu.g/ kg/ day), a medium-dose group (100. mu.g/ kg/ day), a high-dose group (1000. mu.g/ kg/ d) of 4 groups, each group of 10 rats, The body weight growth curve of the rat was drawn daily for 5 days (once a day), and the body weight growth curve of the rat was drawn after daily weighing. After the model was made for 13 weeks, the heart was sacrificed and the thyroid tissue was taken out immediately and stored according to the requirements of the experiment. The blood samples were centrifuged at 4 & deg; C and the serum was isolated and stored at -70 鈩，
本文编号：2503158
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