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1.
尽管规律运动可提高免疫功能,但运动对急性2,3,7,8-四氯二苯并对二噁英(TCDD)暴露导致的免疫抑制作用的影响尚不清楚.Th1/Th2细胞因子平衡是机体免疫平衡的标志之一.为探究运动对急性TCDD暴露大鼠血清Th1/Th2细胞因子平衡的影响,将28只8周龄雄性Wistar大鼠随机分为正常对照组(NC)、运动对照组(EC)、TCDD对照组(TC)和TCDD运动组(ET).TC组和ET组腹腔注射TCDD(10μg·kg-1体重),NC组和EC组腹腔注射等量玉米油.随后,EC组和ET组负重游泳(5%体重),每天30 min,每周6 d,持续4周;NC和TC静养4周.实验结束后称体重、胸腺和脾湿重,计算其相对重量;Elisa法测试血清肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)、白细胞介素-12(IL-12)和白细胞介素-13(IL-13)浓度,并计算IFN-γ/IL-13和IL-12/IL-13比值.结果表明,(1)TCDD暴露明显减小大鼠胸腺相对重量,增大大鼠脾脏相对重量,降低血清TNF-α和IL-12浓度,对血清IFN-γ和IL-13浓度无影响,有升高IL-12/IL-13比值的趋势;(2)TCDD暴露后运动可明显降低血清IL-13浓度,明显升高IL-12/IL-13比值.这表明,急性TCDD暴露通过诱导大鼠胸腺萎缩、脾肿大以及使Th1/Th2平衡向Th2极化而抑制免疫功能.虽然,运动不能避免TCDD暴露所致的胸腺萎缩、脾肿胀,但能通过减轻急性TCDD暴露所致的大鼠血清Th1/Th2相关细胞因子失衡而改善免疫功能.  相似文献   

2.
为了研究2,3,7,8-四氯二苯并二噁英(TCDD)和β-萘黄酮(β-NF)对斑马鱼(Danio rerio)肝脏和鳃CYP1A依赖性7-甲氧基-3-异酚噁唑酮-脱甲基酶(MROD)活性的影响,分别利用不同浓度的TCDD(0、0.05、0.1、0.2、0.4μg·L-1)和β-NF(0、25、50、100、200μg·L-1)对斑马鱼进行水浴暴露,48h后取样测定肝脏和腮MROD活性.结果表明,与对照组比较,TCDD暴露组和β-NF暴露组斑马鱼肝脏和鳃MROD活性均显著增强(p<0.01),且MROD活性的增加与TCDD或β-NF暴露浓度呈现明显的剂量-效应关系.初步推断斑马鱼肝脏和鳃CYP1A依赖性MROD酶活性可能能够作为TCDD或β-NF污染的生物标志物.  相似文献   

3.
观察8周中等强度游泳运动对2,3,7,8-四氯二苯并二恶英(2,3,7,8-tetrachlorodibenzo-p-dioxin,2,3,7,8-TCDD)急性暴露大鼠肝脏氧化应激的影响。以8周龄雄性Sprague Dawley大鼠为研究对象,将大鼠随机分为玉米油静养组(NC组)、玉米油运动组(EC组)、TCDD静养组(NT)和TCDD运动组(ET组)。将TCDD溶于玉米油中,NT和ET组大鼠按照10μg·kg-1(以单位体重计)腹腔注射TCDD,NC和EC组大鼠注射等量玉米油。正式实验开始后,EC和ET组大鼠进行运动(尾部负重5%游泳30min),每周运动5 d,共8周,NC和NT组大鼠不进行任何运动干预。8周后,称重并宰杀大鼠,收集血清和肝组织样本,待测血清天门冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)的活性;肝组织丙二醛(MDA)含量,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及谷胱甘肽过氧化物酶(GSH-Px)的活性。将数据进行多因素方差分析,结果表明,染毒可升高大鼠血清AST的活性,增加肝脏MDA的含量,降低肝脏SOD、CAT和GSH-Px的活性;运动可降低大鼠肝脏GSH-Px的活性;染毒后运动可减少肝脏MDA的含量,升高肝脏SOD、CAT和GSH-Px的活性。研究表明,TCDD急性暴露可导致大鼠肝细胞功能受损,导致大鼠肝脏发生氧化应激。8周有氧运动改善TCDD急性暴露诱导的肝细胞损伤,改善肝脏氧化应激,这可能是运动改善TCDD肝毒性的机制之一。  相似文献   

4.
为了研究二恶英对细胞的代谢毒性,探究其肝毒性的作用机制,以二恶英中毒性最强的2,3,7,8-四氯代二苯并-对-二恶英(TCDD)为代表污染物,以HepG2肝癌细胞为受试对象,采用四甲基偶氮唑蓝(MTT)法和高效液相色谱/串联质谱法考察了TC-DD的24h暴露对HepG2细胞的增殖活性以及细胞的葡萄糖、氨基酸、尿素和甘油等小分子代谢物的影响。结果显示,短暂的TCDD暴露对HepG2细胞的增殖活性无显著影响。24h的TCDD暴露对细胞的葡萄糖消耗量无显著影响,但当TCDD浓度增至1nmol·L-1时,葡萄糖的消耗量表现出一定的降低趋势。0.01nmol·L-1TCDD就会使细胞脯氨酸和谷氨酸的合成能力下降,且谷氨酸的变化表现出明显的剂量-效应关系;TCDD可刺激细胞对缬氨酸、苏氨酸、酪氨酸、甲硫氨酸以及亮氨酸与异亮氨酸的吸收,并具有明显的浓度依赖性。随着TCDD浓度的增加,甘油和尿素产生量的降低趋势逐渐明显,1nmol·L-1TCDD处理24h后,甘油和尿素的产生量仅为对照组的1%和18%。研究表明,TCDD在短时间内使HepG2细胞内的一系列小分子代谢产物发生了不同程度的改变,且呈现出一定的剂量-效应关系。可见,TCDD可通过干扰HepG2肝癌细胞的代谢过程产生毒性。  相似文献   

5.
人核糖核酸酶抑制因子(Human ribonuclease inhibitor, hRI)是细胞质中的一种酸性糖蛋白,可以与血管生长因子(Angiogenin, Ang)紧密结合从而抑制血管形成.利用全基因组合成法合成针对人核糖核酸酶抑制因子基因(hri)的发夹shRNA序列,亚克隆到siRNA表达载体pKD;重组载体经酶切鉴定后,用脂质体法与报告基因绿色荧光蛋白重组融合的人核糖核酸酶抑制因子的逆转录病毒载体pLNCX-EGFP-C1-hri共转染到小鼠黑色素瘤细胞B16中,在荧光显微镜下检测干扰效果.用Image-Pro plus 4.5软件对绿色荧光照片半定量分析干扰效率.结果表明,荧光显微镜显示B16中表达的绿色荧光被干扰,荧光强度半定量分析干扰效率可达80%以上.成功重组构建了针对hri的siRNA表达载体.图5参9  相似文献   

6.
假单胞菌表达载体pYMB03的构建与性能分析   总被引:1,自引:0,他引:1  
恶臭假单胞菌(Pseudomonas putida)是具有强抗逆性能的环境优势菌,构建其质粒表达载体有着明显的应用潜力.将恶臭假单胞菌AB92019菌株中肽聚糖相关脂蛋白编码基因的启动子PoprL和质粒载体pTrcHis-B的多克隆位点片段插入到质粒载体pUCPl8的EcoRL/HInIII位点,获得了重组载体pYMB03.用绿色荧光基因gfp作为标记进行外源蛋白表达的结果表明,该载体能分别在恶臭假单胞菌AB92019菌株和大肠杆菌DH5a菌株中,由启动子PoprL启动组成型表达GFP蛋白并使细胞产生可见荧光.经SDS-PAGE验证,所产生的GFP蛋白分别占细胞总蛋白的12.5%和5.O%.重组菌株YMB001中GFP表达量与菌体培养时间有关,在稳定期后期其相对荧光强度达到最大值(D600nm=l.0),但与培养温度未见相父性.对携带该载体的2株重组恶臭假单胞菌7次168 h继代培养测定,载体pYMB03的稳定性均为100%.  相似文献   

7.
RecA与UvrA是细胞SOS系统中重要的修复蛋白,在细胞DNA损伤后诱导表达.将报告基因绿色荧光蛋白基因(gfpmut3a)分别置于recA和uvrA启动子调控下,构建成质粒pRecAgfp和pUvrAgfp,并转化E.coli DH5α,构建成检测菌株ERS101和EUS101.试验发现,菌株ERS101和EUS101在致畸物吖啶橙处理后,GFP的表达量增高,菌悬液经507nm的蓝光激发后产生的绿色荧光明显增强,且与吖啶橙的浓度具有一定的相关性,即使在0.5μg mL^-1的吖啶橙诱导下也能检测到荧光增强效应.对硝基酚等多种致畸物处理后的检测菌株均有荧光增强效应.图4表1参9  相似文献   

8.
冷诱导RNA结合蛋白(CIRP)是第一种在哺乳动物细胞中被发现的冷休克蛋白,伴随着细胞冷应激过程过量表达.为进一步研究冷诱导RNA结合蛋白CIRP的生物学功能,构建重组BALB/C鼠CIRP的原核表达载体,重组BALB/C鼠CIRP蛋白经NI-NTA亲和树脂纯化后免疫獭兔制备抗CIRP多克隆抗体,以间接ELISA和Western blot检测抗体效价和抗原特异性.本实验成功构建了CIRP的原核表达载体,在E coli XL-1-blue得到了高效表达,利用原核表达包涵体蛋白免疫獭兔获得了高效价的CIRP多克隆抗体,该抗体能识别肝脏和睾丸中天然的CIRP蛋白.图5参14  相似文献   

9.
为了分析鼠Tcp11l1基因的结构和表达,从小鼠睾丸组织总cDNA中扩增鼠Tcp11l1基因的开读框架(Open reading frame,ORF),定向克隆到真核表达载体pEGFP-N1,构建融合表达质粒pTcp11l1-EGFP,转染HEK293细胞,荧光显微镜下观察Tcp11l1基因的亚细胞定位;设计跨小鼠Tcp11l1基因两个外显子的引物,RT-PCR分析此基因在小鼠各组织中的表达情况.并利用生物信息学的方法对鼠Tcp11l1基因的结构进行初步预测.转染pTcp11l1-EGFP后在胞质中能明显看到绿色荧光信号,而在胞核和胞膜中无绿色荧光信号,表明鼠Tcp11l1蛋白定位于细胞质;RT-PCR分析结果表明,鼠Tcp11l1基因在小鼠各组织中广泛表达.生物信息学结果表明,鼠Tcp11l1和鼠Tcp11的蛋白具有相同的TCP11结构域,不能确定是否存在跨膜序列.鼠Tcp11l1基因和鼠Tcp11基因具有相似的亚细胞定位和TCP11结构域,表明这两个基因可能具有相似的受体功能.但是与Tcp11特异表达于睾丸组织的延长精细胞和精子不同,Tcp11l1为广泛表达,说明Tcp11l1可能在多种组织细胞中发挥作用.  相似文献   

10.
2,3,7,8-四氯二苯并对二恶英(2,3,7,8-Tetrachlorodibenzo-p-Dioxin,TCDD)是一种持久性环境有机污染物质,它在有机体内的蓄积性引起研究人员的重视。以青鳉胚胎作为实验动物模型,使用原位杂交和定量聚合酶链锁反应(Polymerase Chain Reaction,PCR)技术从分子水平探讨了TCDD对胚胎耳泡的发育及其毒性作用机制。结果表明,TCDD造成青鳉幼鱼耳泡生成障碍。通过原位杂交和q PCR分析表明,TCDD引起软骨发育的变化与SOX9b表达降低有密切的关联。研究认为青鳉胚胎是一种非常敏感的TCDD模式动物,其耳泡软骨发育以及SOX9b基因表达可能是一种二恶英发育毒性的效应标记物。  相似文献   

11.
为研究2,3,7,8-四氯二苯并对二噁英(TCDD)对体外原代培养大鼠卵巢颗粒细胞活力和雌二醇(Estradiol,E2)、孕酮(Progestone,P)分泌的影响,探索TCDD对卵巢颗粒细胞的毒性作用阈值和程度,对未成熟SD大鼠卵巢颗粒细胞进行了原代培养,并设2组体外染毒实验:终浓度分别为0.1、1、10、100nmol·L-1TCDD染毒24h和10nmol·L-1TCDD染毒1、3、6、18、24h.染毒结束后采用MTT法检测细胞活力,RIA法检测收集培养液中的E2和P含量.结果表明,1、10、100nmol·L-1TCDD可显著抑制大鼠卵巢颗粒细胞活力和E2、P的分泌,与阴性对照、0.1%DMSO组、0.1nmol·L-1TCDD组比较差异均有显著性(p<0.05);10nmol·L-1TCDD染毒6、18、24h可明显抑制细胞活力和E2、P的分泌,与对照组和短期染毒组(1h、3h)差异均有显著性(p<0.05).痕量的TCDD可显著降低大鼠卵巢颗粒细胞活力并抑制细胞E2和P分泌,对大鼠卵巢颗粒细胞的毒性作用阈值可能为1nmol·L-1或更低.TCDD的生殖毒性作用可能与直接对卵巢颗粒细胞的毒性作用和抑制甾体激素的生物合成以及分泌有关.  相似文献   

12.
为探讨2,3,7,8-四氯二苯并二噁英(TCDD)和多氯联苯(Aroclor 1254)联合染毒对大鼠外周血淋巴细胞DNA的损伤效应,将20只雄性Sprague-Dawley(SD)大鼠随机均分为4组,即对照组(橄榄油)、Aroclor 1254单独染毒组(10mg·kg-1)、TCDD单独染毒组(10μg·kg-1)和联合染毒组(TCDD 10μg·kg-1+Aroclor 1254 10 mg·kg-1).大鼠每天灌胃染毒1次,连续染毒6d.染毒过程中记录大鼠的体征和体重.末次染毒后24h取外周血,分离淋巴细胞,采用碱性单细胞凝胶电泳技术(彗星试验)检测外周血淋巴细胞DNA损伤,并采用CASP软件分析各组彗星的尾部DNA百分含量(Tail DNA%)、尾长(Tail Length)和尾矩(Tail Moment).结果表明,染毒结束时TCDD单独染毒和联合染毒组大鼠体重显著低于对照组,且联合染毒组表现更为明显.TCDD单独染毒组和联合染毒组大鼠外周血淋巴细胞DNA可见明显损伤,TailDNA%、Tail Length和Tail Moment均显著高于对照组(p<0.05),且联合染毒组大鼠细胞DNA损伤更为严重,但Arolor 1254单独染毒组大鼠未见明显DNA损伤.析因分析提示TCDD与Aroclor 1254对大鼠外周血淋巴细胞DNA损伤的联合毒性效应为协同作用.本研究结果表明TCDD与Aroclor 1254联合染毒可加重大鼠外周血淋巴细胞DNA损伤,在对PCBs与二噁英的混合暴露进行危险性评估时要注意这种联合毒性作用.  相似文献   

13.
为探明妊娠早期胚胎的丢失是否与卵巢、输卵管、子宫组织受到2,3,7,8-四氯苯并二噁英(TCDD)直接毒害有关,检测了NIH小鼠胚胎着床前期和后期TCDD暴露对胚胎毒性影响的敏感性,并利用免疫组化方法分析了模型动物肝脏、子宫、输卵管和卵巢组织中TCDD所引起的AhR、ARNT以及Cyp1a2分子标记物的变化.检测发现:妊娠第9d,100ng·kg-1·d-1剂量TCDD经口染毒,造成胚胎着床数量减少,且着床前期暴露的影响大于着床后期;子宫蜕膜反应受到明显抑制;胚胎迁移率没有明显变化,但胚胎数量减少.免疫组织化学分析发现正常组小鼠的肝脏、子宫、输卵管和卵巢组织中有AhR和Cyp1a2弱阳性信号表达,ARNT有细胞核的强阳性信号表达;妊娠第1~8d、第1~3d和第4~8d处理组小鼠肝脏、子宫、输卵管和卵巢组织中的AhR、Cyp1a2的阳性面积和光密度值均高于正常组;随处理时间和组织蓄积量的增加,ARNT在组织中的变化由胞核(妊娠第1~3d组)表达到胞浆(妊娠第4~8d组)表达,然后完全无表达(妊娠第1~8d组).以上研究结果表明:TCDD对早期妊娠小鼠子宫、输卵管和卵巢组织中的AhR、ARNT和Cyp1a2的激活和代谢方式与肝脏相同,说明雌性生殖系统中的组织有TCDD蓄积和代谢活性,这可能是导致早期胚胎迁移、着床等过程改变,造成胚胎丢失的重要原因.  相似文献   

14.
The chronic effects low-dose 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were examined on protein expression profiles in rat testis, sperm, and serum gonadal hormones. A total of 32 male rats were randomly divided into three TCDD-exposed groups, administered either 140, 350, or 875 ng TCDD/kg/week for 29 weeks, respectively, and one control group receiving only corn oil. The proteins from rat testis were separated and analyzed by two-dimensional gel electrophoresis and mass spectrometry. TCDD induced significant decreases in sperm counts and serum gonadal hormone levels compared with controls. TCDD altered testicular protein expression levels. Several interesting volume-altered proteins that were related to the reproductive toxicities or other toxicities of TCDD were identified. Among these proteins, PERF15 was the only down-regulated protein; sperm protein SSP411, ubiquitin carboxyl-terminal hydrolase L-3, and eukaryotic translation elongation factor 1 gamma were up-regulated by TCDD. The differentially expressed proteins and other data provide further insight into the mechanisms of reproductive toxicity mediated by low-dose TCDD exposure.  相似文献   

15.
The aim of this study was to investigate the effects of curcumin (CUR) on antioxidant status, body weight (BW) gains, and some reproductive parameters in male rats exposed to subchronic doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Thirty-two rats were divided into four groups. The first group was kept as control. The second group (TCDD group) was given TCDD at a dose of 50 ng·kg?1 BW per day; the third group (CUR group) was treated with CUR at a dose of 80 mg·kg?1 BW per day. The fourth group (TCDD + CUR group) was given TCDD and CUR at the same doses simultaneously. Malondialdehyde (MDA) levels were significantly increased in the TCDD group. In addition, TCDD exposure decreased liver superoxide dismutase (SOD) activity, catalase (CAT) activities of kidney and brain, glutathione peroxidase (GSH-Px) activities of liver, kidney, and brain, and glutathione levels of liver, kidney, and heart. However, CUR treatment with TCDD exposure decreased MDA levels in all tissues and increased SOD activities of liver, kidney, and brain, CAT activity of heart, and GSH-Px activities of heart and brain. TCDD caused a decrease in BW gain, and CUR partially eliminated this effect of TCDD. In addition, while reproductive organ weights, sperm concentration, and sperm motility tended to decrease with TCDD exposure, these effects tended to be close to normal levels by CUR treatment. In conclusion, CUR was seen to be effective in the treatment and prevention of toxicity induced by subchronic TCDD exposure.  相似文献   

16.
The objective of this work was to evaluate potential interactions between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls congeners (PCBs) in rats. Groups of five adult female rats were given 0, 2.5, 25, 250, or 1000?ng TCDD/kg body weight/day or TCDD in combination with a mixture of PCB congeners at a concentration of 2 or 20?µg?kg?1 body weight/day by gavage for 28 days. After the 28-day treatment period, the rats were killed for the analysis of biochemical, liver enzyme activities, and hematological and pathological end points. Growth suppression, increased absolute and relative liver weights, and decreased thymic weight were observed in the 1000?ng TCDD group alone, or the groups receiving a mixture of 1000?ng TCDD and 2 and 20?µg PCBs. TCDD-increased liver and thymic weights were not altered by PCBs; however, growth suppression was more pronounced in animals receiving 1000?ng TCDD and 2?µg PCBs. Increased hepatic microsomal methoxy resorufin-O-demethylase and ethoxy resorufin-O-deethylase activities occurred in 250 and 1000?ng?kg?1 TCDD-treated animals, which were antagonized by PCBs. Effects of 250?ng TCDD on serum cholesterol and liver uridine diphosphate glucuronosyl transferase activity were reduced by 20?µg PCBs. Treatment with 1000?ng TCDD increased serum albumin, decreased liver vitamin A, increased kidney vitamin A, and liver microsomal glutathione-S-transferase activity, which were not affected by PCBs. Decreased hemoglobin, platelet, packet cell volume, and red cell indices were observed in TCDD-treated rats, but no interactive effects were seen. Histopathological evaluation revealed that liver, thyroid, and thymus were the target organs, but the effects of co-exposure to PCBs and TCDD were variable. These results indicate that the mixture effects of PCBs and TCDD may be additive, synergistic, or antagonistic depending on the dose level and end points measured.  相似文献   

17.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has well characterized effects on specific immune responses, but the effects on the innate immune system are less understood. The effect of TCDD on inflammatory responses induced by lipopolysaccharide (LPS) was evaluated in C57BL/6J female mice. Mice were treated with 30?µg?kg?1 TCDD or vehicle once, p.o., and 4 days later, animals received LPS (0.05?×?107?EU?kg?1, i.p.) or vehicle. Inflammatory mediators and the liver injury marker, alanine aminotransferase (ALT), were measured, and liver histology was evaluated. TCDD-treated animals had higher plasma ALT activity than vehicle-treated animals, but the effect was mild and time-dependent. Few changes in liver histopathology were observed, mainly represented in greater steatosis in TCDD/LPS-treated mice compared to mice treated with LPS or TCDD alone. LPS produced a time-dependent increase in the plasma concentrations of interleukins (IL)-6, -10, and -12 and interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein (MCP)-1. With the exception of IL-12, concentrations of each of these mediators were higher in plasma of mice co-treated with TCDD and LPS compared to either agent alone. The dose–response curve for the concentration of IL-6 in plasma suggested that dioxin increased the potency of LPS to cause the release of this cytokine but not the maximal response. Co-treatment with TCDD and LPS also led to greater expression of mRNA for IL-10 and IFN-γ compared to either TCDD or LPS alone. These results suggest that TCDD changes the inflammatory cytokine profile induced by LPS and that LPS enhances the hepatic steatotic response to TCDD.  相似文献   

18.
AzaC预处理增加TCDD对特殊细胞P450基因的诱导   总被引:1,自引:0,他引:1  
利用RT-PCR检测不同物质诱导细胞的CYP基因 mRNA的表达水平.在HepG2细胞,TCDD能诱导CYP1A1、CYP1B1及CYP1A2基因表达,CYP1A1、CYP1B1基因比CYP1A2基因更容易被诱导,用AzaC处理后CYP1B1基因表达无改变;在A549细胞和SPC-A1细胞,Azac预处理后增加了TCDD对CYP1家族的诱导.也就是AzaC增加了CYP1A1、CYP1A2和CYP1B1基因表达水平.图1表1参10  相似文献   

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