首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
缺锌对大鼠胸腺发育影响及机理探讨   总被引:14,自引:1,他引:13  
吴嘉惠  贺泽化 《营养学报》1998,20(3):303-307
目的:研究缺锌对胸腺发育及T淋巴细胞活化与增殖功能的影响。方法:建立大鼠缺锌(ZD)模型,测定胸腺肽、胸腺激素活性、胸腺T淋巴细胞转化、活化T淋巴细胞钙离子和活性钙调蛋白等。结果:1.ZD组的血清、毛、胸腺细胞锌含量低于对照(AL)组(P<0.01)。2.ZD组的胸腺重量、指数和细胞大小低于AL组(P<0.01或P<0.05)。3.ZD组胸腺的胸腺肽含量、胸腺素活性低于AL组(P<0.01)。4.ZD组胸腺细胞的DNA、RNA和蛋白质含量低于AL组(P<0.01)。5.ZD组胸腺细胞中增殖期细胞(S+G2/M)、增殖指数(PI)低于AL组(P<0.01)。6.ZD组胸腺细胞内cAMP含量与cAMP/cGMP比值高于AL组(P<0.01)。7.ZD组胸腺细胞内的Ca2+、CaM、IL-2、IL-2Rα及T细胞增殖率低于AL组(P<0.01)。8.ZD组胸腺T淋巴细胞内的锌离子与Ca2+、CaM、IL-2、IL-2Rα、T淋巴细胞增殖率呈正相关(P<0.01);Ca2+与IL-2、IL-2Rα呈正相关(P<0.01);CaM与IL-2、IL-2Rα呈正相关(P<0.01)。结论:适量锌有促进胸腺发育、胸腺激素活?  相似文献   

2.
高锌饲料对大鼠胸腺发育及其作用机理的探讨   总被引:8,自引:0,他引:8  
通过建立大鼠高锌(ZH)模型,研究高锌对胸腺发育的影响及其作用机理。结果表明:(1)ZH组的体重、体重增长值、饲料效价均非常显著低于配对(PF)组;(2)ZH组的血清、毛发、股骨及胸腺细胞锌含量均非常显著地高于PF组;(3)ZH组的胸腺重量、胸腺指数、胸腺细胞大小、胸腺肽含量和胸腺素活性,均非常显著地低于PF组;(4)ZH组的胸腺细胞内DNA、蛋白质含量低于,而G1/G0期细胞(%)数高于PF组;(5)ZH组胸腺细胞内cAMP、cAMP/cGMP比值非常显著高于PF组,增殖指数(PI)与cAMP、cAMP/cGMP比值呈负相关;与cGMP呈正相关,均P<0.01;(6)ZH组血清钙低于PF组,而胸腺细胞内Ca2+高于PF组,P<0.05。结果提示,适量锌有促进胸腺发育、增殖的作用,而高锌则反之。其机理可能是高锌影响细胞内腺苷酸环化酶系统,并与胞浆内游离钙和钙调蛋白的调节活性有关。  相似文献   

3.
急性髓系白血病细胞自分泌GM-CSF及其凋亡的研究   总被引:1,自引:1,他引:0  
要探讨急性髓系白血病(AML)原代细胞自分泌的粒细胞-巨噬细胞集落刺激因子(GM-CSF)和重组人粒细胞-巨噬细胞集落刺激因子(rhGM-CSF)对原代AML细胞凋亡的影响,应用放射免疫技术检测GM-CSF水平,DNA电泳检查梯状条带及流式细胞仪检测细胞凋亡率和BcI-2蛋白表达的阳性细胞率和相对荧光强度(MFI)。结果在5例原代AML细胞体外培养中,3例的培养上清液可检测到GM-CSF,其自发细  相似文献   

4.
多环芳香烃空气浓度和焦碳炉工人多环芳香烃-DNA加合的相关性G.Assennatoetal.不同多环芳香烃(PAH)的加合物对人类可有相似的血清学改变,可形成免疫反应抗御单个的PAH-DNA加合物。据此理论,本研究用周围血液白细胞BNA加合物作为PA...  相似文献   

5.
苯DNA加合物的组织分布及其与细胞遗传毒性的关系   总被引:3,自引:0,他引:3  
李桂兰  尹午山 《卫生研究》1995,24(5):260-262
用P1增强的32P-后标记方法测定了经腹腔注射染苯小鼠不同组织DNA加合物的分布及其与苯引起的外周血白细胞(WBC)减少、淋巴细胞微核形成及骨髓细胞染色体畸变的关系。结果表明:1.苯在小鼠骨髓、肝脏和外周血WBC均可形成DNA加合物,其加合物含量以骨髓最高,肝脏次之,WBC最低。本结果与苯的代谢及毒性作用特点相一致。2.DNA加合物形成与细胞毒性有关系,DNA加合物量增加,淋巴细胞微核及骨髓细胞染色体畸变亦增加,而外周血白细胞数明显减少,显示细胞遗传毒性和细胞毒性均增大。本研究为DNA加合物作为生物学监测指标,筛选高危人群提供了有力的实验依据。  相似文献   

6.
本文用短波紫外线(UVC)照射人胎盘和小牛胸腺DNA取得UV-DNA(紫外线导致变性的DNA),并分别对新西兰家兔进行长达9周的免疫。结果表明:人胎盘UV-DNA未能引起免疫应答,其抗UV-DNA未能检出。而小牛胸腺的抗UV-DNA的效价为1:8。用兔抗小牛胸腺UV-DNA检测32例红斑狼疮(SLE)病人和21例正常人的血清,发现SLE病人血清中UV-DNA的阳性率为65.6%,正常人为5%。两者的差异有非常显著性意义(P<0.01)。提示血清中UV-DNA可望成为SLE诊断和疗效观察及人群接触紫外线时健康监测的特异和敏感指标之一。  相似文献   

7.
维生素A对小鼠造血微环境影响的研究   总被引:7,自引:0,他引:7  
李廷玉  杨莉 《营养学报》1999,21(4):388-392
目的: 探讨维生素A(VA)对造血微环境的影响,揭示VA缺乏影响红系造血的机制。方法:免疫细胞化学(SP)法检测视黄酸受体(RARa)蛋白,原位杂交技术动态检测原癌基因c-jun、c-fos和粒-单集落刺激因子(GM-CSF)m RNA 的表达,检测细胞因子生物活性和基质细胞层粘附能力。结果: (1)全反式视黄酸(ATRA)诱导的小鼠骨髓基质细胞条件培养液(BMSCCM)能显著促进红系早期祖细胞(BFU-E)的增殖(P< 0.01)。(2)ATRA明显促进基质细胞层的粘附能力。(3)RARa 蛋白在实验组和对照组BMSC持续表达,ATRA对其表达水平无影响。(4)实验组BMSC与对照组相比c-fos、c-jun m RNA的表达水平在30m in 即有显著性差异(P< 0.01),持续表达至60m in,120m in 降至对照组水平。实验组GM-CSFm RNA的表达在30m in,60m in 与对照组水平相比无显著性差别,直至120m in 才表现出显著性差异(P< 0.01)。结论: VA促进小鼠BMSC分泌造血细胞生长因子并增强其粘附能力,通过调节BMSC中c-jun、c-fos的信号传导通路调节BMSC分泌GM-C  相似文献   

8.
接触室内煤烟的肺癌患者多环芳烃DNA加合物的研究   总被引:5,自引:0,他引:5  
本实验是为了探索宣威肺癌病因和肺癌早期危险性评价方法做一点尝试,应用32P后标记法检测了宣威30例(实验组)、昆明10例(对照组)肺癌病人的纤维支气管镜(纤支镜)刷落细胞的多环芳烃(PAH)-DNA加合物。结果表明宣威肺癌病人的PAH-DNA加合物水平远远高于对照组。该结果从分子水平上证明宣威室内煤烟污染与肺癌有直接联系,DNA加合物的检测可以作为人群危险性评价的指标。  相似文献   

9.
3种醛类化合物对DNA的交联生成作用   总被引:10,自引:0,他引:10  
采用溴化乙锭荧光法测定3种醛类污染物对小牛胸腺DNA的交联生成作用,结果,甲醛、乙醛均可引起小牛胸腺DNA发生交联,甲醛交联率间存在明显的剂量反应关系(甲醛r=09384,P<0001),乙醛的剂量反应关系不显著(r=02947,P<005),没有检测到丙烯醛对小牛胸腺DNA的交联作用,分析与丙烯醛的空间位阻最大可能存在一定关系  相似文献   

10.
姜向阳  陈亚丽 《现代预防医学》1997,24(2):129-130,140
观察高频(频率200 ̄1000kHz)作业人员62名血中LPO、GSH-Px、SOD、CP、IgA、IgG、IgM、cGMP、cAMP的变化,探讨慢性低强度高频辐射对作业人员脂质过氧化和免疫功能的影响机制。结果表明:高频作业人员血中LPO、GSH-Px与对照组差异显著,cGMP、cAMP和IgA、IgG、IgM显著高于对照组;SOD和CP的改变无统计学意义;高频淬火机的危害较大。  相似文献   

11.
苯醌-脱氧鸟苷酸加合物的结构及化学特性初步研究   总被引:2,自引:1,他引:1  
目的 测定苯醌(BQ)与脱氧鸟苷酸(dGMP)反应形成的加合物结构与化学特性。方法 高效液相色谱—质谱联机技术及紫外分光光度法。结果 苯醌与脱氧鸟苷酸反应形成两种可检测的加台物Ad1和Ad2,质谱显示Ad1的分子量为437,在不同pH条件下的特征紫外吸收光谱及结合键类型测定结果表明,Ad1为BQ与dGMP共价结合而成,推测结合位点在dGMP的N—1和N^2位,分子式为C16H16O8N5P。BQ与小牛胸腺DNA反应水解产物经高效液相色谱(HPLC)分离同样检出了与Ad1具有相同保留时间的化合物。Ad2分子量为241,其分子式为C11H702N5,可能是由BQ进攻dGMP的N—9位并脱掉糖基所得。结论 苯醌可在体外试管反应条件下形成DNA加合物,其中一种主要的加合物结构为(3’-经基)—1,N^2—苯乙烯基—2’—脱氧鸟苷—5’—磷酸。  相似文献   

12.
OBJECTIVE: The immune system is dependent on purines and pyrimidines as building blocks for DNA and RNA synthesis to enable rapid cell proliferation and protein synthesis. Emerging evidence suggests that dietary nucleotides optimize immune function. We investigated whether growth and function of human immune cells were affected by an exogenous source of nucleotides during specific antigen challenge. METHODS: Peripheral blood mononuclear cells from healthy individuals (n = 10) were stimulated with influenza virus antigen and either DNA sodium from fish soft roe (DNA), RNA from bakers yeast (Saccharomyces cerevisiae) (RNA), 2' deoxyadenosine 5'-monophosphate sodium (dAMP), 2' deoxycytidine 5'-monophosphate sodium (dCMP), 2' deoxyguanosine 5'-monophosphate sodium (dGMP), 2' deoxyuridine 5'-monophosphate sodium (dUMP) or thymidine sodium (TMP). Growth effects were ascertained by measuring the amount of tritium-labeled thymidine, incorporated into cell DNA. Cell function was measured by detection of IFN-gamma, TNF-alpha and IL-10 production. RESULTS: Specific nucleotide derivatives alone did not affect the growth of healthy peripheral blood mononuclear cells. However, the nucleotide derivatives influenced immune cell growth and cytokine secretion when cocultured with specific antigen. DNA, RNA, dAMP, dCMP and dUMP increased influenza virus antigen induced immune cell proliferation. In contrast dGMP and TMP inhibited the antigen-induced growth response. RNA and dAMP cocultured with virus antigen significantly increased peripheral blood mononuclear cell secretion of IFN-gamma, IL-10 and TNF-alpha. DNA increased virus antigen-induced immune cell secretion of IFN-gamma only, whereas dUMP significantly increased secretion of IL-10 only. dGMP completely inhibited virus-triggered IFN-gamma secretion, whereas TMP did not change the virus induced secretion pattern of measured cytokines. CONCLUSION: Nucleotide derivatives affect growth and function of specific virus antigen-stimulated human immune cells in vitro.  相似文献   

13.
目的:研究苯乙烯的DNA加合特性。方法:采用高效液相色谱法研究苯乙烯-7,8-氧化物(S0)、苯乙烯、苯乙醇酸(MA)、苯乙醛酸(PGA)和DNA的加合反应。结果:苯乙烯、MA、PGA不与DNA发生加合反应;SO可与脱氧鸟苷酸及脱氧腺苷酸发生加合反应,生成以共价键结合的加合物。结论:苯乙烯进入机体后,通过其活性中间代谢物SO与DNA起加合作用,SO攻击DNA脱氧鸟苷酸及脱氧腺苷酸形成加合物,如果在细胞复制前所形成的DNA加合物没有被修复或者被错误修复的话,就有可能导致基因突变。苯乙烯的其他代谢物未见此效应。  相似文献   

14.
苯乙烯-DNA加合特性的研究   总被引:8,自引:0,他引:8  
目的 研究苯乙烯的DNA加合特性。方法 采用紫外光谱移动法测定苯乙烯-7,8-氧化物(SO)、苯乙烯、苯乙醇酸(MA)、苯乙醛酸(PGA)、苯乙烯巯基尿酸(UMA)和DNA的加合反应;以^32P后标记法研究SO-DNA加合物;以气相色谱-质谱、核磁共振研究SO-DAN加合物的结构。结果 苯乙烯、MA、PGA和UMA不与DNA发生加合反应;SO分别在DNA脱氧鸟苷碱基上的O^6位、N^2位形成6种加合物。结论 苯乙烯进入机体后,通过其活性中间代谢物SO与DNA起加合作用,SO攻击DNA脱氧鸟苷碱基上的O^6位、N^2位形成加合物,如果在细胞复制前所形成的DNA加合物没有被修复或者被错误修复的话,就有可能导致基因突变,产生化学损伤。苯乙烯的其他代谢物未见此效应。  相似文献   

15.
目的 探讨甲醛、乙醛和丙烯醛对DNA的损伤机制.方法 采用体外测试系统,应用高效液相色谱法(HPLC)对甲醛、乙醛、丙烯醛及其在人体内的代谢产物甲酸、乙酸、羟丙基巯基尿酸与4种单脱氧核苷酸的加合反应进行研究.结果 经HPLC分离检测,甲醛、醋醛与脱氧鸟苷酸发生加合反应,而丙烯醛、甲酸、醋酸和羟丙基巯基尿酸难以与脱氧鸟苷酸发生加合反应或加合物产量过低,初步确定了甲醛、乙醛与4种单脱氧核苷酸结合的优势反应核苷酸.结论 甲醛、乙醛能够与DNA的脱氧鸟苷酸结合而体现遗传特性.  相似文献   

16.
Two novel rare earth complexes, Y(III) complex (1) and Eu(III) complex (2), with naringenin-2-hydroxy benzoyl hydrazone ligand were synthesized and characterized. The interaction of the two metal complexes and the free ligand with calf thymus DNA (CT DNA) was investigated by electronic absorption spectroscopy, fluorescence spectroscopy and viscosity measurement. All the experimental evidences indicate that these three compounds can strongly bind to CT DNA via an intercalation mechanism. The intrinsic binding constants of the Y(III) complex (1), Eu(III) complex (2) and the free ligand with CT DNA were 2.1x10(4), 8.5x10(4) and 1.6x10(4)M(-1), respectively. Furthermore, the antioxidant activity of the metal complexes was determined by hydroxyl radical scavenging method in vitro.  相似文献   

17.
We have previously reported that metabolism of a series of pyrrolizidine alkaloids in vitro and in vivo generated a set of (+/-)6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts. It has also been shown that the levels of the DHP-derived DNA adduct formation correlated closely with the tumorigenic potencies of the mice fed with different doses of riddelliine. Retronecine is the necine base and the structurally smallest chemical of the retronecine-type pyrrolizidine alkaloids. Although it has been reported that microsomal metabolism of retronecine generated DHP as a metabolite, it was yet not known whether metabolism of retronecine in vivo could generate DHP-derived DNA adducts and if formed, whether or not the levels of DNA adducts were comparable with those formed from the other tumorigenic retronecine-type pyrrolizidine alkaloids, such as riddelliine, retrorsine, and monocrotaline. In this investigation, the in-vitro and in-vivo metabolic activation of retronecine was studied. Rat liver microsomal metabolism of retronecine in the presence of calf thymus DNA resulted in the formation of a set of DHP-DNA adducts. The metabolism of retronecine N-oxide under similar conditions also formed the similar set of DHP-DNA adducts. The level of DNA adducts from retronecine was enhanced when metabolism by liver microsomes from phenobarbital (PB)-induced rats were used. The DHP-DNA adducts were also found in the liver DNA of female F344 rats treated with retronecine or retronecine N-oxide. The highest level of the total DHP-DNA adducts was found in liver DNA from the rats treated with dehydroretronecine (DHR). The order of the levels of DNA adducts in the liver DNA samples from rats treated with various pyrrolizidine alkaloids was: DHR > riddelliine > riddelliine N-oxide > retronecine > retronecine N-oxide. The results indicate that 1) retronecine can be metabolized to form DHP by rat liver microsomal enzymes and interacts with DNA to produce DHP-DNA adducts and 2) retronecine N-oxide undergoes the biotransformation to the parent compound, retronecine. The results from this and our previous findings strongly suggest that formation of DHP-DNA adducts may be a potential biomarker for pyrrolizidine alkaloid carcinogenesis.  相似文献   

18.
The repair activities of silybin (SLB) and its analogues towards the oxidizing deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts are investigated by pulse radiolytic techniques. On pulse irradiation of nitrous oxide saturated 2.0 mM dGMP aqueous solution containing 0.1 mM silybin at neutral pH, the transient absorption spectrum of the dGMP hydroxyl radical adducts decreases with the formation of the phenoxyl radical of silybin within tens of microseconds, indicating that there is a repair reaction between the dGMP hydroxyl radical adduct and silybin. The rate constant of the repair reaction is calculated to be 1.0 x 10(9) M(-1)s(-1) for silybin. The repair activity of hesperetin (HESP), naringin (NAN) and naringenin (NAR) towards hydroxyl radical adducts of dGMP are also studied.  相似文献   

19.
丙烯腈对DNA交联作用研究   总被引:3,自引:0,他引:3       下载免费PDF全文
目的 应用牛胸腺DNA和染毒丙烯腈 (AN)小鼠精细胞研究AN对DNA的交联作用 ,研究AN毒作用的分子机制。方法 应用溴化乙锭荧光法测定加或不加S9条件下AN对牛胸腺DNA交联作用。雄性小鼠随机分为阴性对照 ,3、 6、 9、 12、 18和 2 4mg/kgAN染毒组 ,每组 2只。腹腔注射染毒 1次 ,于染毒第 2 4h处死小鼠 ,分离精细胞 ,观察细胞存活率 ,测定精细胞DNA交联率。结果 加与不加S9条件下 ,AN对牛胸腺DNA均未产生交联作用。小鼠精细胞DNA交联率在 3、 6、 9mg/kgAN剂量范围内随剂量增加而升高 ,呈明确的剂量 反应关系 (r =0 93 5 ,P <0 0 5 )。结论 在体外实验中AN对牛胸腺DNA未产生交联作用 ,对小鼠精细胞DNA在较低剂量时产生了交联作用 ,高剂量产生断裂作用和交联作用。AN对精细胞的DNA交联作用可能是产生生殖毒作用的分子机制之一  相似文献   

20.
Lambda DNA-fragmenting actions of ascorbic acid (AsA) and triose reductone (TR) in the presence of Cu2+ were studied. The mixture of AsA or TR and Cu2+ caused a marked fragmentation of lambda DNA (3.2 X 10(7) daltons) within the first 1 min of reaction. Further incubation resulted in accumulation of the most abundant species of fragmented lambda DNA having a molecular weight of 1.3 X 10(5) daltons. The mixture of AsA or TR and Cu2+ fragmented calf thymus DNA to produce the fragmented DNA of which 5'-OH terminal groups have a mixture of free OH groups and phosphodiester linkage. The mixture of AsA or TR and Cu2+ was also found to fragment lambda DNA to produce dCMP predominantly as 5'-OH terminal nucleotides.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号