五鹤续断对大鼠局灶性脑缺血再灌注损伤各脑区一氧化氮含量及一氧化氮合酶活性的影响

目的探讨五鹤续断醇提液对大鼠局灶性脑缺血再灌注损伤中各脑区一氧化氮(NO)浓度及一氧化氮合酶(NOS)活性的影响。方法用线栓法建立大鼠脑缺血再灌注动物模型,用比色法测定再灌注后不同时间点脑组织中NO含量和NOS活性。结果模型组大脑皮质和海马中NO含量和NOS活性明显增高,五鹤续断醇提液可降低大脑皮质和海马中NO含量和NOS活性,各时点NO含量与NOS活性成显著正相关。结论五鹤续断醇提液对大鼠局灶性脑缺血再灌注损伤有明显保护作用,其机制可能与降低NO和NOS表达水平有关。     

氢气对脑缺血再灌注大鼠海马一氧化氮及其合酶的影响

目的探讨氢气治疗对急性脑缺血再灌注损伤大鼠海马NO和一氧化氮合酶(NOS)的影响。方法选择SD大鼠72只,随机分为3组:假手术组、模型组和治疗组(腹腔注射2%氢气饱和生理盐水),每组24只,每组又分为6、24h2个时间点。采用线栓法制作大鼠大脑中动脉缺血再灌注模型。免疫组织化学方法测定海马NOS的表达;硝酸还原酶法测定海马组织匀浆中NO含量;NOS检测试剂盒检测海马组织提取液中NOS的活性。结果模型组治疗6h海马NOS阳性细胞、NO含量及NOS活性明显高于假手术组,而治疗组上述指标较模型组明显下降(P<0.05);模型组治疗24h海马NOS阳性细胞、NO含量及NOS活性明显高于假手术组,差异有统计学意义(P<0.05),但治疗组与模型组比较,差异无统计学意义(P>0.05)。结论氢气治疗可减少缺血后海马组织中NO含量及NOS活性,对海马缺血再灌注损伤起到一定的保护作用。     

联合水蛭注射液后处理对脑缺血损伤大鼠磷酸化内皮型一氧化氮合酶表达的影响

目的观察缺血后处理(IPOC)联合水蛭注射液后处理对脑缺血损伤大鼠磷酸化内皮型一氧化氮合酶(p-e NOS)mRNA及其蛋白表达的影响。方法 SD大鼠40只,随机分为假手术组(SO组)、缺血再灌注对照组(MCAO组)、IPOC组、IPOC+水蛭注射液后处理组(P-L组)四组。采用线栓法制备大鼠大脑中动脉缺血(MCAO)模型及IPOC模型,应用实时荧光定量PCR和Western印迹技术检测p-e NOS mRNA及其蛋白表达变化。结果 SO组有少量p-e NOS mRNA及其蛋白表达;MCAO组大鼠脑缺血再灌注24 h缺血半暗带p-e NOS表达较SO组明显增高(P<0.05);IPOC组二者的表达水平较MCAO组明显升高(P<0.05,P<0.01);P-L组能较IPOC组进一步升高其表达(P<0.05,P<0.01)。结论脑IPOC可能通过诱导p-e NOS的表达发挥其神经保护作用,水蛭注射液后处理可进一步促进其表达而发挥神经保护作用。     

局灶缺血早期大鼠脑组织一氧化氮合酶表达的变化

目的 研究局灶缺血早期大鼠脑组织一氧化氮合酶(NOS)表达变化情况,探讨NO和NOS在脑缺血性损伤中的作用机制.方法 建立大鼠大脑中动脉阻塞(MCAO)局灶脑缺血模型,选择大鼠脑缺血10、30、60 min 3个时点,采用免疫组织化学SABC方法检测脑组织NOS表达,应用光镜、透射电镜观察海马神经元的形态学改变.结果 脑缺血早期10～30 min大鼠脑组织NOS活性上升至高峰,脑缺血后30～60 min逐渐下降.电镜观察脑缺血后30 min海马神经元损伤最为严重.结论 NO和NOS在脑缺血早期造成脑组织损伤较为严重.     

姜黄素对大鼠肝缺血再灌注早期肝组织一氧化氮表达的影响

目的:探讨姜黄素对大鼠肝脏缺血再灌注早期损伤微循环的影响.方法:将大鼠随机分为假手术组、对照组和实验组(姜黄素40 mg/kg,2次给药).通过检测再灌注早期1、3 h血清转氨酶水平、肝组织中一氧化氮(nitricoxide,NO)、一氧化氮合酶(nitricoxide synthase,NOS),诱导型一氧化氮合酶(inducible nitricoxide synthase,iNOS)mRNA及内皮型一氧化氮合酶(endothelium nitricoxide synthase,eNOS)mRNA水平,以及肝组织病理学检查来评价姜黄素对大鼠肝脏缺血再灌注早期损伤微循环的影响.结果:相对于对照组,姜黄素可降低大鼠肝脏缺血再灌注早期损伤1、3 h血清谷丙转氨酶(ALT)的水平(603.8 U/L±64.5 U/L vs 758.1 U/L±114.7U/L,837.1 U/L±33.3 U/L vs 1012.7 U/L±119.8 U/L,均P<0.01)和谷草转氨酶(AST)的水平(605.7 U/L±65.7 U/L vs 779.5 U/L±124.3 U/L,849.6 U/L±36.0 U/L vs 1027.8 U/L±139.8 U/L,均P<0.01);改善肝组织病理学损害;减少肝脏缺血再灌注早期损伤1、3 h肝组织由iNOS产生的NO蛋白水平(0.455±0.056 vs 0.594±0.087.0.492±0.040 vs 0.671±0.079,均P<0.01);降低肝脏缺血再灌注早期损伤1、3 h肝组织iNOS mRNA的表达强度(0.426±0.075 vs 0.569±0.073,0.527±0.066vs 0.702±0.089,均P<0.01).结论:姜黄素可通过减轻肝组织中由iNOS产生的NO生成,来改善肝缺血再灌注早期损伤中微循环的紊乱,从而减少对肝缺血再灌注肝实质细胞的损伤.     

天麻酚类成分对脑缺血模型大鼠海马一氧化氮和一氧化氮合酶的影响

目的探讨天麻酚类成分对脑缺血大鼠海马NO和一氧化氮合酶(NOS)的影响。方法采用双侧颈总动脉永久性结扎法,造成大鼠脑缺血模型。造模6周后,SD大鼠40只随机分为5组,假手术组、模型组、尼莫地平组、天麻酚类成分高剂量组(高剂量组)和天麻酚类成分低剂量组(低剂量组),每组8只。给药3周后,比色法检测海马NO含量和NOS活性,免疫印记法检测大鼠海马NOS 3种亚型(nNOS,iNOS,eNOS)的表达。结果与假手术组比较,模型组大鼠海马NO含量、NOS活性及nNOS和iNOS表达明显升高,eNOS表达明显降低;与模型组比较,尼莫地平组和高剂量组大鼠海马NO含量、NOS活性及nNOS和iNOS表达明显降低,eNOS表达明显升高;低剂量组大鼠NOS活性和iNOS表达明显降低,差异有统计学意义(P<0.05,P<0.01)。结论天麻酚类成分对脑缺血大鼠海马NO损伤有保护作用。     

川芎嗪减轻大鼠心肌缺血再灌注损伤炎症反应及机制

目的观察川芎嗪预处理对大鼠心肌缺血再灌注损伤炎症反应的影响并探讨其可能的机制。方法 48只雄性SD大鼠随机分为假手术组、缺血再灌注组、川芎嗪组、左旋-硝基-精氨酸甲酯组以及川芎嗪+左旋-硝基-精氨酸甲酯组,假手术组左前降支近端穿线但不结扎,其余四组给予结扎前降支缺血35 min,再灌注120 min。光镜观察大鼠心肌组织结构变化,测定缺血心肌组织超氧化物歧化酶活性和丙二醛含量及髓过氧化物酶、白细胞介素1β、一氧化氮含量,逆转录聚合酶链反应和免疫印迹法测定心肌内皮型一氧化氮合酶mRNA和蛋白的表达水平。结果与缺血再灌注组相比,川芎嗪预处理能减少心肌白细胞浸润,增加心肌组织超氧化物歧化酶活性,降低丙二醛含量及髓过氧化物酶活性,降低白细胞介素1β水平,增加一氧化氮含量及心肌内皮型一氧化氮合酶mRNA和蛋白的表达水平,左旋-硝基-精氨酸甲酯显著抑制上述指标的变化并取消了川芎嗪所致的内皮型一氧化氮合酶mRNA和蛋白表达水平的增加。结论川芎嗪预处理能减少大鼠心肌缺血再灌注损伤的炎症反应,其机制可能与上调内皮型一氧化氮合酶表达,增加内源性一氧化氮水平有关。     

心肌缺血/再灌注过程对心电图QRS合值、心肌酶、NOS和MDA的影响

目的 观察心肌缺血/再灌注过程心电图QRS合值、血清心肌酶及心肌组织一氧化氮合酶（NOS）、丙二醛（MDA）的变化。方法 采用分别结扎兔冠状动脉左回旋支10、20、30和40 min并再灌60 min制备4组缺血/再灌注动物模型,另设假手术组,分别于再灌注60 min时观察QRS合值,并同时测定天门冬氨酸氨基转移酶（AST）、乳酸脱氢酶（LDH）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、NOS和MDA。结果 ①QRS合值变化:缺血40 min组QRS合值较假手术组、结扎10 min组及结扎20 min组明显增高（P<0.05）;②心肌酶:缺血40 min组AST及LDH较其他各组明显增高（P<0.05）,缺血/再灌注组CK均明显高于假手术组（P<0.05）,缺血30 min组与缺血40 min组较假手术组CK-MB明显增高（P<0.05）;③NOS:缺血40 min组NOS较假手术组明显增高（P<0.05）;④MDA:缺血40 min组MDA较假手术组明显增高（P<0.05）; 结论 缺血40 min组,LDH及CK-MB、NOS、MDA均明显增高,QRS合值水平亦增高。     

一氧化氮与脑缺血一再灌流损伤

脑缺血－再灌流时一氧化氮发挥复杂的作用，本文对一氧化氮的特点、一氧化氮合酶的分布、缺血－再灌流时脑内一氧化氮的变化规律与毒性作用机制及一氧化氮与缺血半暗带的联系等作一综述。     

原花青素对脑缺血再灌注小鼠脑组织细胞因子、一氧化氮合酶和血脑屏障的影响

目的探讨葡萄籽原花青素对缺血再灌注小鼠脑组织细胞因子、一氧化氮合酶和血脑屏障通透性的影响。方法采用夹闭小鼠双侧颈总动脉30 min再灌注72 h的脑缺血再灌注模型,并于双侧颈总动脉夹闭时及再灌注后每隔24 h分别腹腔注射蒸馏水、葡萄籽原花青素(10、20及40 mg/kg)和尼莫地平(2 mg/kg)。在处死动物前1 h经尾静脉注射2%伊文思蓝,采用ABC-ELISA法检测脑组织中白细胞介素1β和白细胞介素10含量,采用分光光度法检测脑组织中一氧化氮合酶活性及伊文思蓝含量。同时光镜观察小鼠海马CA1区脑组织的病理变化。结果与假手术组相比,缺血再灌注组脑组织中白细胞介素1β含量、一氧化氮合酶活性及伊文思蓝含量明显增高(P<0.01),而白细胞介素10含量降低,但无统计学意义。与缺血再灌注组相比,葡萄籽原花青素及尼莫地平治疗组脑组织中白细胞介素1β含量、一氧化氮合酶活性及伊文思蓝含量有不同程度的降低,而白细胞介素10含量有不同程度的升高。病理学组织检查发现,葡萄籽原花青素能改善脑缺血再灌注所造成的神经细胞损伤,减少神经细胞坏死。结论葡萄籽原花青素可能通过降低小鼠脑缺血再灌注时一氧化氮合酶活性和促炎因子白细胞介素1β含量,提高抗炎因子白细胞介素10含量进而降低血脑屏障的通透性而发挥脑保护作用。     

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

AIM: To investigate the dynamic change and role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis (NEC) is associated with the levels of nitric oxide synthase (NOS) in the mucosa of the affected intestine tissue. METHODS: Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide (IPS). Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS: The LPS-injected pups showed a significant increase in injury scores versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION: nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.     

脓毒症时各型一氧化氮合酶在大鼠心脏中的表达及其可能机制

目的研究脓毒症时各型一氧化氮合酶(NOS)在心脏中的损伤作用及其机制。方法成年雄性Wistar大鼠腹腔注射脂多糖(LPS)制备脓毒症模型。应用多导生理仪监测大鼠心功能变化;用分光光度计法测定大鼠心肌组织NOS的活性;用RT-PCR和Western blot对大鼠心肌组织各型NOS的表达进行半定量分析。结果给予LPS后6h大鼠心肌收缩和舒张功能受损下降,心肌中iNOS的活性明显升高,eNOS和nNOS(合称cNOS)活性减弱;RT-PCR和Western blot结果显示,给予LPS后cNOS的表达减少,给予LPS后iNOS表达量明显增加。结论脓毒症时,iNOS、nNOS和eNOS的表达和活性发生改变;心肌细胞上iNOS表达及活性升高,这些变化可能在心功能降低中发挥作用。     

一氧化氮及其合酶在哮喘发病机制中的作用

探讨一氧化氮及其合酶在哮喘发病机制中的作用。方法 采用哮喘豚鼠模型，将豚鼠分为４组；１．哮喘组，用１０％卵白蛋白腹腔注射１ｍｌ致敏，２周后用１％卵白蛋白超声雾化吸入致其哮喘发作．２；肾上腺皮质激素预防组；诱喘同哮喘组，在每次诱喘前腹腔滴注地塞米松０．５ｍｇ／ｋｇ。３．硝基精氨酸甲酯预防组；诱喘同哮喘组，每次诱喘产腹腔注射ＬＮＮＡ０．４ｍｇ／ｋｇ。４．正常对照组；用生理盐水代替诱喘剂。每组分别测定其     

Co-expression and modulation of neuronal and endothelial nitric oxide synthase in human endothelial cells

Despite originally identified in neurones, the neuronal type of nitric oxide synthase (nNOS) is present also in cardiac and skeletal myocytes. Whether nNOS is functionally expressed in human endothelial cells--as the endothelial enzyme (eNOS)--is unknown. Human umbilical vein endothelial cells (HUVEC) were studied under control culture conditions and after 48 h treatment with cytomix (human tumour necrosis factor-alpha, interferon-gamma and E. coli endotoxin). We tested: (i) localisation and expression of nNOS and eNOS proteins by immunostaining and immunoblotting; (ii) activity of nNOS and eNOS by measuring L-arginine to L-citrulline conversion with 1-(2-trifluoromethylphenyl)imidazole (TRIM), a specific nNOS antagonist, in sub-cellular fractions; (iii) intracellular cGMP levels, as a marker for nitric oxide production, after TRIM pre-treatment, by radioimmunoassay. nNOS protein was expressed in the cytosolic fraction and immunolocalised in cultured HUVEC, and co-localised with the eNOS protein in frozen sections of the human umbilical cord. nNOS protein contributed to total L-citrulline production as TRIM selectively and dose-dependently reduced L-citrulline synthesis in the cytosolic but not particulate fraction of HUVEC. Similarly, TRIM reduced intracellular cGMP content both at baseline and after stimulation with a calcium ionophore. Cytomix down-regulated the expression and function of both nNOS and eNOS while no inducible NOS (iNOS) was detected. In conclusion, a functional neuronal type of NOS is co-expressed with the endothelial NOS type in HUVEC, suggesting a possible role for nNOS in regulation of blood flow.     

Chronic ethanol exposure impairs neuronal nitric oxide synthase in the rat intestine

BACKGROUND: Nitric oxide (NO), synthesized by neuronal (nNOS), endothelial (eNOS), and inducible (iNOS) nitric oxide synthases, plays an essential role in the physiological functions of the gastrointestinal (GI) tract. Chronic ethanol intake has been shown to interfere with several of these physiological functions, leading to the pathological alterations observed in alcoholic individuals. Our aim therefore was to investigate the effects of chronic ethanol consumption on NOS isoforms in different GI segments. METHODS: Rats received either 20% aqueous ethanol solution or water for 8 weeks. Tissue samples of the duodenum, jejunum, ileum, and colon of the rats were used for measurement of the NOS activity, protein content, and nNOS immunohistochemistry. Anti-HuC/D immunohistochemistry was used to determine the total number of neurons. RESULTS: Measurement of the physiological constitutive NOS (cNOS) activity revealed a 20 times higher activity in the colon than in the small intestine and after chronic ethanol treatment demonstrated a significant decrease in the jejunum, ileum, and colon, while in the duodenum it remained unchanged compared with the control group. The physiological iNOS activity was higher in the ileum and colon than in the duodenum and jejunum, and these levels were not significantly affected by ethanol. Neuronal nitric oxide synthase immunohistochemistry revealed a significant decrease in the numbers of immunostained cells in all investigated intestinal segments, while the total number of myenteric neurons remained constant. The nNOS protein content measured by Western blotting indicated a significant decrease in the colon after ethanol consumption, while in other intestinal segments change was not detectable. CONCLUSIONS: This study has demonstrated for the first time that chronic ethanol consumption has a differential effect on NOS activity, NOS protein content, and the number of nitrergic neurons in different intestinal segments, suggesting that chronic ethanol administration affects the NO pathways in the enteric nervous system.     

大鼠主动脉球囊拉伤后一氧化氮合酶表达的变化

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Cystic fibrosis lung disease: the role of nitric oxide

This review summarizes current knowledge about the role of nitric oxide (NO) in cystic fibrosis (CF) lung disease. NO is endogenously produced by a group of enzymes, the NO synthases (NOSs). There are three isoforms of NOS, each encoded by different genes: neuronal (nNOS), immune or inducible (iNOS), and endothelial (eNOS) nitric oxide synthase.(1) They all form NO and L-citrulline by enzymatic oxidation of L-arginine. This reaction requires a number of cosubstrates, including molecular oxygen and tetrahydrobiopterin. It is now known whether all three isoenzymes are constitutively expressed in cells of the respiratory tract and that their gene expression is inducible.(2,3) NO production by iNOS, the "high-output" NOS, is stimulated by bacterial lipopolysaccharide (LPS) as well as proinflammatory cytokines such as interleukin (IL)-1gamma, IL-2, interferon (IFN)-gamma, and tumor necrosis factor (TNF). In contrast to nNOS and eNOS, activation of iNOS does not require an increase in intracellular Ca(2+) concentration.     

甲状腺激素对大鼠小脑,海马,嗅脑神经元型一氧化氮合酶基因表达的调节

目的　观察 15日龄大鼠小脑 ,海马 ,嗅脑一氧化氮 (NO)含量 ,一氧化氮合酶 (NOS)活性的变化及甲状腺激素对上述部位神经元型一氧化氮合酶 (nNOS)基因表达的调节。方法　采用丙基硫氧嘧啶 (PTU)给孕母鼠灌胃造成仔鼠甲减动物模型 ;采用NO ,NOS生化测定法及nNOSmRNA半定量逆转录聚合酶链反应 (RT PCR)法。结果　无论正常组还是甲减组 ,NO含量 ,NOS活性及nNOSmRNA转录均以小脑为最高 ,嗅脑次之 ,海马最低 (P <0 .0 5 ) ;正常组NO含量 ,NOS活性nNOSmRNA转录均高于甲减组 (P <0 .0 1)。结论　提示甲状腺激素对nNOS基因表达有上调作用 ,NO信号系统可能参与大鼠小脑 ,海马 ,嗅脑等区甲状腺激素缺乏所造成的脑损害过程。     

Ethanol effects on nitric oxide production in cerebral pial cultures

BACKGROUND: Although alcohol abusers are known to have higher incidences of hemorrhagic cerebrovascular diseases, it is not known whether these changes are associated with ethanol (EtOH) action on nitric oxide (NO) production in the cerebrovascular cells. The purpose of this study was to examine the effects of EtOH treatment on basal and cytokine-induced NO production in cortical pial cultures. METHODS: Cell cultures for this study included murine primary pial vascular cells, primary glial cells and cortical neurons. These cells were exposed to cytokines or EtOH for 24 to 48 hr. The culture media were used for measurement of nitrite, as an indication for NO release, and lactate dehydrogenase (LDH), as an index of cell membrane integrity. In addition, immunocytochemical determinations were carried out to identify cell types and to assess inducible nitric oxide synthase (iNOS). RESULTS: Exposure of primary pial vascular cultures to cytokines that consisted of interleukin-1 beta (IL-1 beta; 250 pg/mL) and interferon-gamma (IFNgamma; 2 ng/mL) or to EtOH (50 to 100 mM) for 24 to 48 hr significantly elevated NO production. NO production could be attenuated by N-nitro-L-arginine (N-arg), a nonspecific NOS inhibitor, or aminoguanidine (AG), an iNOS inhibitor. Increased iNOS immunoreactivity was observed in cytokines- or EtOH-treated pial cells. When pial cells were cocultured with cortical neurons, prolonged EtOH exposure led to a large increase in NO production as well as LDH release. However, this increase was not observed in pial culture alone or in mixed cortical culture. Nevertheless, inhibition of NO production with N-arg or AG did not alter the EtOH-induced LDH release in the pial cells cocultured with cortical neurons. CONCLUSION: These results show that EtOH exposure led to increased production of NO in primary pial cell culture. In mixed culture that contained cortical neurons and pial cells, EtOH induced increase in NO as well as LDH release, which is an indication of loss of cell membrane integrity. However, EtOH-mediated LDH release in mixed cortical pial cultures was not a consequence of the increase in NO production by these cells. Studies that use mixed cortical-pial cultures may provide a unique in vitro system for examining the interactions among glial cells, neurons, and cerebrovascular cells.