不同阶段铅暴露对大鼠妊娠结局及胎盘MMP-9表达的影响

目的通过观察孕期不同时段铅暴露对妊娠结局及胎盘MMP-9的表达影响,评价孕早期、孕后期及孕全程铅暴露的毒性特点及毒性机制。方法采用原子吸收光谱仪测定孕期不同阶段低水平铅暴露后的大鼠孕末期血铅水平。0.025%醋酸铅对实验组孕鼠染毒,根据大鼠孕期3周推算足月剖宫产,观察统计异常分娩情况,记录胎盘质量、仔鼠数、仔鼠质量。免疫组化法测定胎盘滋养细胞MMP-9的表达。结果孕早期染铅对孕末期血铅水平及胎盘质量的影响较大,孕晚期染铅对仔鼠重量的影响较明显,孕全程染铅对孕末期血铅水平、胎盘质量及仔鼠质量均有明显影响,孕全程染铅组其胎盘MMP-9表达下降。结论铅具有生殖毒性及胚盘毒性,孕期不同时段铅暴露导致不同的妊娠结局。胎盘MMP-9表达下降可能是铅致胎盘损伤的病理机制之一。     

PSD-95参与大鼠孕期铅暴露对子代海马突触影响的实验研究

目的:研究大鼠孕期铅暴露后子代海马突触变化与PSD-95表达改变的相关性,探讨铅暴露损伤学习记忆功能的机制。方法:通过饮用0.02%醋酸铅水溶液建立孕期铅暴露模型,利用原子吸收分光光度仪检测血铅,透射电镜技术检测海马突触密度,蛋白印记技术检测子代大鼠海马组织中VGLUT、VGAT和PSD-95的表达。结果:对照组和铅暴露组雄性21 d大鼠体重分别为(55.73±4.23)g和(56.01±5.97)g,无显著差异(P0.05);对照组与铅暴露组雄性21 d大鼠血铅分别为(10.2±2.1)μg/L和(301.2±34.8)μg/L,血铅水平明显升高(P0.01);对照组与铅暴露组雄性21 d大鼠单位面积突触数目分别为32.79±2.03和23.46±1.97,突触密度明显减少(P0.01);铅暴露后,VGAT的表达量没有明显变化(P0.05),VGLUT和PSD-95的表达量明显减少(P0.01)。结论:PSD-95表达减少引起海马兴奋性突触数目的下降是发育期铅暴露损伤学习记忆功能的可能机制。     

新生儿脐带血铅水平及其影响因素的研究

目的了解石家庄市新生儿脐带血铅水平及其相关的影响因素.方法采用石墨炉原子吸收光谱法.于2003年4～6月对在我院产科分娩的98例产妇进行静脉血和脐带血铅含量的测定,并进行家庭社会环境和健康状况问卷调查,分析对脐带血铅水平的影响因素.结果(1)98例脐带血铅平均为49μg/L,≥100μg/L者12例,对应的产妇静脉血铅平均为54μg/L,≥100μg/L者17例.(2)产妇血铅与脐带血铅呈正相关,产妇血铅和孕期被动吸烟、马路上滞留时间是胎儿期铅暴露的危险因素,孕期补铁和补钙是胎儿期铅暴露的保护因素.结论本组新生儿脐带血铅水平与家庭和环境因素有关,由此产生的不利影响应引起重视.     

珠海地区胎儿铅暴露状况及其影响因素的探讨

目的:了解珠海市人群的胎儿铅暴露水平及其影响因素。方法:在珠海市收集脐带血标本81份,用电感耦合高频等离子体发射光谱仪测定血铅浓度,并以面谈问卷的形式对相应的81名产妇进行了社会环境及家庭生活因素调查。结果:81例脐带血血铅水平呈正态分布,范围在0590μg/L。平均值为150μg/L。脐带血血铅水平超过目前认为的安全界限(100μg/L)占67.9%。研究还发现孕妇居住房屋年代、孕妇居住地、孕期食用罐头食品是胎儿铅暴露的危险因素。多元Logistic回归分析发现,食用罐头食品对脐血铅水平的贡献在考虑了其他掺杂因素的影响后仍有统计学意义。结论:目前珠海市环境铅污染状况可能对胎儿的发育产生不利影响。     

西安地区1286例孕妇静脉血微量元素血铅检测结果分析

目的铅能通过胎盘,当母亲血铅水平大于50μg/L时,就已经对胎儿产生了影响。笔者通过随机对西安市2010年10～12月份怀孕1～8个月的孕妇静脉血血铅含量的测定。提高人们对低浓度血铅对孕妇造成的危害引起高度重视。方法北京博晖创新光电技术有限公司生产的专门用于临床检测血铅的BH2100原子吸收分光光度仪。结果 1286例孕妇静脉血中大于50μg/L小于100μg/L是98例占7.62%;大于100μg/L小于200μg/L的是2例占0.15%,无轻度、中度、重度铅中毒。结论胎盘对血铅无屏障作用,虽然孕妇血铅的正常值是0-100μg/L,但是有资料表明超过50μg/L,就会对胎儿造成危害。1286例孕妇中血铅值大于50μg/L的占到了7.78%,要足够引起人们的重视。     

CD4+与T淋巴细胞干扰素γ/诱导型一氧化氮合酶/一氧化氮通路在脐带间充质干细胞移植治疗重症肌无力中的作用

背景：有研究表明,CD4+、干扰素γ/诱导型一氧化氮合酶/一氧化氮通路与重症肌无力的发生密切相关。 目的：探讨CD4+ T细胞与干扰素γ/诱导型一氧化氮合酶/一氧化氮通路在脐带间充质干细胞移植治疗重症肌无力中的作用机制。 方法：建立重症肌无力大鼠模型,并进行脐带间充质干细胞经静脉移植治疗,同时设立对照组。流式细胞术检测移植后大鼠腋窝淋巴结细胞CD4+的表达,ELISA法检测其干扰素γ的表达,Griess试剂和比色法检测一氧化氮和一氧化氮合酶水平。 结果与结论：移植1周后,移植组大鼠腋窝淋巴结的淋巴细胞CD4+的表达显著高于模型组(P < 0.01),干扰素γ、一氧化氮及诱导型一氧化氮合酶水平显著低于模型组(P < 0.01)。证实,脐带间充质干细胞移植可上调重症肌无力模型大鼠淋巴细胞CD4+的表达,并调节干扰素γ/诱导型一氧化氮合酶/一氧化氮通路,下调一氧化氮水平,以减轻机体的免疫损伤。     

铅暴露环境下血栓调节蛋白在胚胎发育中的作用

目的探讨不同孕期铅暴露状态下,大鼠血栓调节蛋白(thrombomodulin,TM)的变化以及在胚胎发育中的作用。方法 108只大鼠随机分为A,B,C,D 4组,A组为对照组,B,C,D为实验组。0.025%醋酸铅对实验组大鼠染铅。原子吸收光谱法测定孕鼠血铅水平。ELISA法测定孕鼠血及胎盘TM表达。结果实验组孕鼠血铅水平、血浆TM和胎盘TM水平均显著高于对照组(P<0.01),而实验组子鼠体重显著低于对照组(P<0.01)。血铅水平与血浆TM和胎盘TM之间以及血浆TM与胎盘TM水平之间呈显著相关,r值分别为:0.9063;0.9697和0.9702。结论孕期不同阶段的铅暴露对TM表达的影响不同,TM可能在维持胎盘组织凝血-抗凝平衡和胚胎发育中发挥重要作用。     

生长分化因子15在子痫前期胎盘滋养细胞中的表达及意义

目的探讨生长分化因子-15（GDF-15）在子痫前期患者胎盘滋养细胞中的表达,探讨其在子痫前期发病机制中的作用。方法选择2009年12月至2010年10月在青岛市市立医院住院分娩的子痫前期孕妇140例,其中早发型轻度子痫前期孕妇35例（早发轻度组）,晚发型轻度子痫前期孕妇35例（晚发轻度组）,早发型重度子痫前期孕妇35例（早发重度组）,晚发型重度子痫前期孕妇35例（晚发重度组）;另选同期健康孕妇35例为对照组。采用RT—PCR检测胎盘滋养细胞中GDF-15mRNA的表达量;采用免疫组化方法检测胎盘滋养细胞中GDF-15蛋白的表达。结果RT—PCR显示子痫前期各组胎盘滋养细胞中GDF-15mRNA表达水平均高于对照组,差异有统计学意义（P〈0．05）;但子痫前期各组间分别比较,差异无统计学意义（P〉0．05）。免疫组化显示GDF-15表达于胎盘滋养细胞的细胞浆和细胞外基质中,并在各组胎盘滋养细胞中均表达。子痫前期各组胎盘滋养细胞中GDF-15蛋白表达水平均高于对照组组,差异有统计学意义（P〈0．05）;但子痫前期各组间分别比较,差异无统计学意义（P〉0．05）。结论GDF-15在子痫前期胎盘滋养细胞中表达升高,GDF-15的表达水平变化可能与子痫前期发病有关。     

内皮型、诱导型一氧化氮合酶在乳腺癌中的表达

目的 :研究内皮型一氧化氮合酶 (eNOS)、诱导型一氧化氮合酶 (iNOS)在乳癌中表达及与淋巴结转移的关系。方法 :采用免疫组化S P法检测 60例乳癌中eNOS和iNOS的表达。结果 :eNOS和iNOS阳性在乳癌中表达率分别为 75 0 %和71 7%。在淋巴结转移组和无淋巴结转移组中eNOS阳性表达率分别为 66 7%和 83 3 % ,两组间差异无统计学意义 (χ2 =2 2 2 ,P >0 0 5) ,而iNOS在淋巴结转移和无转移组中阳性表达率分别为 53 3 %和 90 0 % ,两组间差异有统计学意义 (χ2 =9 93 ,P <0 0 1 )。结论 :内皮型、诱导型一氧化氮合酶在乳腺癌中高表达 ;iNOS的表达与乳腺癌的淋巴转移相关     

Nitric oxide-mediated mechanism of neuronal nitric oxide synthase and inducible nitric oxide synthase expression during hypoxia in the cerebral cortex of newborn piglets

Previously, we have shown that hypoxia results in increased generation of nitric oxide free radicals in the cerebral cortex of newborn piglets that may be due to up-regulation of nitric oxide synthases, neuronal nitric oxide synthase and inducible nitric oxide synthase. The present study tests the hypothesis that hypoxia results in increased expression of neuronal nitric oxide synthase and inducible nitric oxide synthase in the cerebral cortex of newborn piglets and that the increased expression is nitric oxide-mediated. Newborn piglets, 2-4 days old, were divided to normoxic (n=4), hypoxic (n=4) and hypoxic-treated with 7-nitro-indazole-sodium salt, a selective neuronal nitric oxide synthase inhibitor (hypoxic-7-nitro-indazole-sodium salt, n=6, 1 mg/kg, 60 min prior to hypoxia). Piglets were anesthetized, ventilated and exposed to an FiO2 of 0.21 or 0.07 for 60 min. Cerebral tissue hypoxia was documented biochemically by determining ATP and phosphocreatine. The expression of neuronal nitric oxide synthase and inducible nitric oxide synthase was determined by Western blot using specific antibodies for neuronal nitric oxide synthase and inducible nitric oxide synthase. Protein bands were detected by enhanced chemiluminescence, analyzed by imaging densitometry and the protein band density expressed as absorbance (OD x mm(2)). The density of neuronal nitric oxide synthase in the normoxic, hypoxic and hypoxic-7-nitro-indazole-sodium salt groups was: 41.56+/-4.27 in normoxic, 61.82+/-3.57 in hypoxic (P<0.05) and 47.80+/-1.56 in hypoxic-7-nitro-indazole-sodium salt groups (P=NS vs normoxic), respectively. Similarly, the density of inducible nitric oxide synthase in the normoxic, hypoxic and hypoxic-7-nitro-indazole-sodium salt groups was: 105.21+/-9.09, 157.71+/-13.33 (P<0.05 vx normoxic), 117.84+/-10.32 (p=NS vx normoxic), respectively. The data show that hypoxia results in increased expression of neuronal nitric oxide synthase and inducible nitric oxide synthase proteins in the cerebral cortex of newborn piglets and that the hypoxia-induced increased expression is prevented by the administration of 7-nitro-indazole-sodium salt. Furthermore, the neuronal nitric oxide synthase inhibition prevented the inducible nitric oxide synthase expression for a period of 7 days after hypoxia. Since administration of 7-nitro-indazole-sodium salt prevents nitric oxide generation by inhibiting neuronal nitric oxide synthase, we conclude that the hypoxia-induced increased expression of neuronal nitric oxide synthase and inducible nitric oxide synthase is mediated by neuronal nitric oxide synthase derived nitric oxide. We speculate that during hypoxia nitric oxide-mediated up-regulation of nitric oxide synthases will continue the perpetual cycle of nitric oxide generation-->NOS up-regulation-->nitric oxide generation resulting in hypoxic neuronal death.     

一氧化氮/诱导型一氧化氮合酶在动脉粥样硬化过程中的作用

 目的：探讨一氧化氮（NO）/诱导型一氧化氮合酶（iNOS）在动脉粥样硬化（atherosclerosis,AS）过程中的动态变化,分析其对动脉粥样硬化形成过程的影响。方法：将60只SD大鼠随机分成2组：对照组及AS组,每组30只。AS组采用维生素D3腹腔注射联合高脂饲料饲养的方法构建动脉粥样硬化模型。用相关生化方法检测血清各项生化指标：总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、空腹血糖和钙离子,比色法检测血清NO浓度,并对主动脉行HE染色,免疫组化技术检测iNOS蛋白表达,将所得数据进行统计分析,用简单线性相关分析NO与钙离子及动脉粥样硬化指数的相关性。结果：90 d后成功构建了主动脉中膜钙化型动脉粥样硬化模型。血清NO浓度在动脉粥样硬化过程中逐步下降,各组间差异均有统计学意义（均P<0.05）。动脉粥样硬化过程中动脉粥样硬化指数与钙离子呈正相关,与NO呈负相关。在90 d的AS组粥样斑块区免疫组化技术检测到iNOS蛋白表达。结论:在动脉粥样硬化形成过程中,主动脉粥样斑块区iNOS蛋白高表达,但血清NO浓度逐渐降低,NO抗动脉粥样硬化作用减弱。     

Analysis of connections between nitric oxide synthase neurons in the myenteric plexus of the guinea-pig small intestine

Summary In the myenteric plexus of the guinea-pig ileum, a sub-population of descending interneurons contains nitric oxide synthase. Final neurons in descending motility pathways, inhibitory circular muscle motor neurons, also contain nitric oxide synthase. In this study we used ultrastructural immunocytochemistry to determine whether nitric oxide synthase descending interneurons provide inputs to all nitric oxide synthase neurons. The presence of nitric oxide synthase inputs to 35 nitric oxide synthase nerve cells from three animals was examined. Nine nerve cells from one ganglion were studied in serial section. Every nerve cell received inputs (close contacts and synapses) from nitric oxide synthase terminals. The number of inputs to the nine serially sectioned neurons ranged from 13 to 45. The inputs were found in about equal numbers on the cell bodies and the dendrites. There was no significant correlation between the size of nitric oxide synthase neurons and the number of nitric oxide synthase inputs they received. There was also no correlation between the number of nitric oxide synthase inputs and the number of 5-hydroxytryptamine inputs (determined in a previous study) received by nitric oxide synthase neurons. Random sections through an additional 26 nitric oxide synthase neurons (seven in the same ganglion and 19 from another two myenteric ganglia from different animals) were examined and nitric oxide synthase synapses and close contacts were observed on each neuron. Nitric oxide synthase interneurons and motor neurons are morphologically indistinguishable. However, since all nitric oxide synthase neurons that were examined received inputs from nitric oxide synthase terminals, the nitric oxide synthase descending interneurons appear to provide inputs to both the nitric oxide synthase inhibitory motor neurons and descending interneurons. Hence the nitric oxide synthase descending interneurons are likely to play a direct role in descending motility reflexes, although nitric oxide does not appear to be the primary transmitter at neuro-neuronal synapses.     

Evidence for nitric oxide and nitric oxide synthase activity in proximal stumps of transected peripheral nerves.

Nitric oxide may be liberated as an inflammatory mediator within injured peripheral nerve trunks. We evaluated the proximal stumps of injured peripheral nerve stumps that later form neuromas or regenerative nerve sprouts, for evidence of local nitric oxide elaboration and activity. Proximal stumps were created in male Sprague-Dawley rats by sectioning of the sciatic nerve and resection of its distal portions and branches. There was striking physiological evidence of nitric oxide activity at the tips of 48-h and 14-day-old proximal nerve stumps. We detected local nitric oxide-mediated hyperemia of both extrinsic plexus and endoneurial microvessels that was reversible, in a dose-dependent stereospecific fashion, by the broad-spectrum nitric oxide synthase inhibitors, Nomega-nitro-L-arginine-methyl ester or Nomega-nitro-L-arginine, but not by 7-nitroindazole, an inhibitor with relative selectivity for neuronal nitric oxide. Immunohistochemical studies provided evidence for the localization of nitric oxide generators at the same sites. In 48-h but not 14-day stumps increased expression of two isoforms of nitric oxide synthase was detected: endothelial nitric oxide and to a much lesser extent neuronal nitric oxide synthase. Both isoforms appeared in axonal endbulb-like profiles that co-localized with neurofilament immunostaining. Western immunoblots identified a band consistent with endothelial nitric oxide synthase expression. In 14-day stumps with early neuroma formation, but not 48-h stumps, there was staining for immunological nitric oxide synthase in some endoneurial and epineurial macrophages. Total nitric oxide synthase biochemical enzymatic activity, measured by labelled arginine to citrulline conversion, was increased in 14-day but not 48-h stumps. Injured peripheral nerves have evidence of early nitric oxide action, nitric oxide synthase expression and nitric oxide activity in proximal nerve stumps. Nitric oxide may have an important impact on the regenerative milieu.     

Immunohistochemical localization of inducible and endothelial constitutive nitric oxide synthase in neoplastic and autoimmune thyroid disorders

AIM: To investigate the distribution of nitric oxide synthase in tissues derived from patients with autoimmune or neoplastic disorders of the thyroid gland in order to test whether the expression of inducible nitric oxide synthase or endothelial constitutive nitric oxide synthase (two subtypes of EC 1.14.13.39) may be related to the inflammatory activity or degree of neoplasia. EXPERIMENTAL DESIGN: The expression of nitric oxide synthases was examined by immunohistochemistry in tissues from patients with either Hashimoto's thyroiditis (n=6), hyperplastic glands (Graves' disease) (n=7), adenomas (n=8), multinodular goitres (n=7), papillary carcinomas (n=4) or follicular carcinomas (n=5). RESULTS: Expression of inducible nitric oxide synthase was found in 22 of the tissues and was not specific for any of the examined thyroid disorders. Expression of endothelial constitutive nitric oxide synthase was found in some of the epithelial cells in all the tissues. There was no correlation between the intensity and distribution of the immunostaining and the thyroid disorders. CONCLUSION: Demonstration of nitric oxide synthase cannot be used for diagnostic purposes. The expression of endothelial constitutive nitric oxide synthase in all tissues indicates that the enzyme may be of importance for the function or growth of the thyroid epithelial cells.     

氧化低密度脂蛋白和一氧化氮合酶在人主动脉内膜中的表达及相关意义

目的：研究氧化低密度脂蛋白(OX-LDL)和一氧化氮合酶(NOS)阳性细胞在正常成人及动脉粥样硬化患者主动脉内膜中的表达及相关意义。方法：选取正常成人和动脉粥样硬化患者主动脉标本,以免疫组化SP法、NADPH—d酶组化方法分别检测OX—LDL和NOS阳性细胞在内膜中的表达。结果：动脉粥样硬化的主动脉壁内膜层OX—LDL阳性表达强于正常的主动脉,而NOS阳性表达弱于正常的主动脉,且两种表达呈负相关。结论：主动脉壁内膜沉积的OX—LDL可抑制内膜细胞NOS活性,OX—LDL和NO在动脉粥样硬化过程中有相互促进的共同致病机制。     

Corticosterone and phenytoin reduce neuronal nitric oxide synthase messenger RNA expression in rat hippocampus.

The production and release of the corticosteroids, namely the glucocorticoids and the mineralocorticoids, are regulated by various stimuli, including stress. Previous studies from our laboratory have shown that chronic exposure to stress or to stress levels of glucocorticoids produces atrophy of the apical dendrites of CA3 pyramidal neurons in the hippocampus. This stress-induced dendritic remodeling is blocked by the anti-epileptic drug phenytoin, which suppresses glutamate release, and also by N-methyl-D-aspartate receptor antagonists. These results suggest an interaction between glucocorticoids and excitatory amino acids in the development of stress-induced atrophy of CA3 pyramidal neurons. Since nitric oxide is proposed to play an important role in mediating both the physiological and pathophysiological actions of excitatory amino acids, we examined the regulation of neuronal nitric oxide synthase messenger RNA expression by corticosterone and phenytoin in the rat hippocampus. The expression of neuronal nitric oxide synthase messenger RNA in hippocampal pyramidal neurons and granule neurons of the dentate gyrus was unaffected by 21-day administration of corticosterone (40 mg/kg), phenytoin (40 mg/kg) or the combination of corticosterone and phenytoin. However, in hippocampal interneurons, corticosterone/ phenytoin co-administration led to a significant reduction in neuronal nitric oxide synthase messenger RNA levels when compared with vehicle controls. These results suggest that, during exposure to stress levels of corticosterone, phenytoin inhibits glucocorticoid-induced atrophy of CA3 pyramidal neurons by reducing neuronal nitric oxide synthase expression in hippocampal interneurons. Moreover, these results may provide another example of synaptic plasticity in the hippocampus mediated by nitric oxide synthase.     

Localization of nitric oxide synthase and effects of nitric oxide donors on the human Fallopian tube.

The objective of the study was to assess the plausible existence of a nitric oxide (NO) system within the human Fallopian tube and to examine the effects of NO on tubal contractility. Tissue was obtained from fertile women at operations due to non-tubal diseases. Production of NO and sites of nitric oxide synthase (NOS) activity were assessed by the use of NADPH diaphorase staining and by immunoblots as well as immunohistochemistry for the isoforms of NOS. Effects of NO on tubal contractility in vitro were examined by adding either of two NO donors (nitroglycerin, spermine NONOate) or an analogue of its second messenger (8-bromo cyclic GMP). The production of NO was indicated by positive NADPH diaphorase staining. In immunoblots, endothelial and inducible NOS were demonstrated in all samples analysed. By immunohistochemistry, moderate staining for endothelial NOS was demonstrated in the luminal epithelial cells and in the endothelial cells of blood vessels. Moderate staining for inducible NO synthase was seen in smooth muscle cells and weak staining in epithelial cells. Nitroglycerin, spermine NONOate and 8-bromo cGMP all resulted in a concentration-dependent inhibition of contractility with significant contractility inhibition at 10(-7) mol/l, 10(-6) mol/l and 10(-5) mol/l respectively. The study demonstrates the existence of an endogenous NO system, which may be of physiological importance in Fallopian tube function.     

Endothelial nitric oxide synthase gene polymorphisms and diabetic nephropathy: A HuGE review and meta-analysis

Candidate-gene association studies that examined the association between polymorphisms of endothelial nitric oxide synthase (NOS3) gene (G894T, 4b/a, and T786C) and diabetic nephropathy or diabetes leading to severe nephropathy produced inconclusive results. Thus, a meta-analysis of all candidate-gene association studies with endothelial nitric oxide synthase genotyping (7401 cases and 8046 controls) was conducted. Other study designs, such as family-based association studies and genome-wide linkage and association studies were also reviewed for supportive evidence of implication of endothelial nitric oxide synthase gene in diabetic nephropathy. The meta-analysis showed that G894T is significantly associated with diabetic nephropathy and diabetes leading to severe nephropathy in type 2 diabetics and in East Asians, respectively. Concerning the 4b/a polymorphism and its relationship to diabetes leading to severe nephropathy, a significant association was shown for East Asians. Heterogeneity between studies was in general high. There was no differential magnitude of effect in large versus small studies. One genome-wide linkage scan provided evidence of linkage nearby the endothelial nitric oxide synthase locus. Studies exploring gene and environment interactions with endothelial nitric oxide synthase polymorphisms may help understand better the genetics of diabetic nephropathy.