血管内皮生长因子在尾悬吊模拟失重大鼠肺组织中表达的研究

目的：研究尾悬吊模拟失重大鼠肺组织血管内皮生长因子的变化。方法：采用尾悬吊模拟失重，分为悬吊7 d和21 d及相应对照4组，每组10只健康雄性SD大鼠，共40只大鼠。并采用免疫组织化学技术检测肺组织的血管内皮生长因子表达情况。结果：7 d尾悬吊模拟失重大鼠肺组织血管内皮生长因子的表达水平明显高于正常对照组（P<0.05），且21 d悬吊组模拟失重大鼠肺组织血管内皮生长因子的表达水平仍较高（P<0.05），但增高程度已明显低于7 d悬吊组。结论：在模拟失重条件下肺组织血管内皮生长因子的表达水平增高，并且随着时间延长增高程度会有所降低.     

大鼠肢体缺血再灌注后肺组织一氧化氮合酶的变化

目的:研究正常大鼠肺组织内一氧化氮合酶(NOS)的分布及肢体缺血再灌注(LIR)后肺组织内NOS分布及活性的变化。方法:用止血带复制肢体缺血再灌注模型,利用β-NADPH-d组织化学方法、计算机图像分析系统及分光光度法,观察对照组大鼠肺内NOS的分布及LIR组肺内NOS分布及活性的变化。结果:组织学上显示,对照组大鼠呼吸道包括支气管、细支气管、终末细支气管、肺泡管的上皮细胞和血管内皮细胞NOS表达均阳性,肺泡上皮细胞NOS表达阴性;LIR组上述肺组织阳性部位NOS表达增强,且出现血管平滑肌细胞、肺泡上皮细胞NOS表达阳性;生化测定结果显示,LIR组与对照组比较,NOS活性增强,NO₂^-/NO₃^-水平增多。结论:一氧化氮不仅参与肺的生理过程,而且在LIR后急性肺损伤(ALI)病理生理过程中可能发挥重要作用。     

尾悬吊模拟失重大鼠胃黏膜超微结构改变及氧化应激损伤

目的 探讨尾悬吊模拟失重对大鼠胃黏膜组织超微结构和氧化应激的影响.方法 健康雄性Wistar大鼠88只,按随机数字表分为11组(n=8),采用尾悬吊法建立模拟失重大鼠动物模型,各组大鼠分别尾悬吊0h(正常对照组)、6h、12h、1d、2d、3d、5d、7d、14d、21 d、28 d.实验结束后观察各组大鼠胃黏膜组织病理改变,检测胃黏膜组织超氧化物歧化酶(SOD)、丙二醛(MDA)和一氧化氮(NO)含量,免疫组化法检测胃黏膜组织诱生型一氧化氮合酶(NOS2)和环氧化酶2(COX2)的表达.结果 透射电镜下可见尾悬吊模拟失重大鼠胃黏膜部分腺细胞核皱缩畸形,染色质浓缩边聚,线粒体肿胀,嵴断裂、溶解,空泡变性,粗面内质网扩张.上述改变在尾悬吊14d、21d、28 d比较明显.与正常对照组比较,尾悬吊1d、5d、14 d、21 d、28 d组大鼠胃黏膜组织SOD含量明显升高(均P＜0.05);尾悬吊12h、14d、21 d、28 d组大鼠胃黏膜组织MDA含量明显升高(均P＜0.05);尾悬吊12h、2d、3d、5d、14d、28d组大鼠胃黏膜组织NO含量明显升高(均P＜0.05).免疫组化显示,尾悬吊6h、12h、1d、2d大鼠胃黏膜组织NOS2和COX2表达明显增强,随后表达减弱;尾悬吊14d、21 d、28 d表达再度增强.结论 尾悬吊模拟失重可导致大鼠胃黏膜组织超微结构改变和NOS2、COX2表达变化.     

尾部悬吊大鼠胸主动脉、肺动脉超微结构变化的动态观察

目的 观察模拟微重力时大小循环动脉血管超微结构重塑随时间变化的差异,为微重力后立位耐力降低的机制研究积累资料.方法 用透射电镜观察-30°尾部悬吊7 d(TS7组)、14 d(TS14组)及对照组大鼠胸主动脉、肺动脉壁超微结构的变化.结果 TS7组胸主动脉内皮细胞表面出现绒毛状突起,部分线粒体空泡变性,内皮下基膜有分层,内弹力板较厚,且厚度不均匀,内弹力板下出现大量的胶原纤维;TS14组胸主动脉内皮细胞变性较明显,部分内皮细胞基质致密化,基膜复层化,内弹力板有破碎,弹力纤维增多.TS7组肺动脉部分内皮细胞突起,细胞内出现脂滴,内皮细胞基膜出现分层状改变,弹力板变薄、断裂,其下方可见收缩型平滑肌及合成型平滑肌细胞;TS14组肺动脉内皮细胞空泡变性较明显,内弹力板未见明显改变,弹力板内外均可见较多的胶原纤维和弹力纤维,内弹力板下方以收缩型平滑肌为主.结论 TS7组大鼠胸主动脉和肺动脉出现损伤和增殖并存,以肺动脉较明显;TS14组肺动脉趋于形成新的稳定结构,而胸主动脉新稳定结构还未形成.模拟微重力时大小循环血管发生了结构重塑,大小循环血管重塑的时间过程不同归因于模拟微重力初期由下体转移而来的体液进入大小循环高峰期的时间差.     

尾部悬吊大鼠胸主动脉、肺动脉超微结构变化的动态观察

目的观察模拟微重力时大小循环动脉血管超微结构重塑随时间变化的差异,为微重力后立位耐力降低的机制研究积累资料。方法用透射电镜观察-30°尾部悬吊7d(TS7组)、14d(TS14组)及对照组大鼠胸主动脉、肺动脉壁超微结构的变化。结果TS7组胸主动脉内皮细胞表面出现绒毛状突起,部分线粒体空泡变性,内皮下基膜有分层,内弹力板较厚,且厚度不均匀,内弹力板下出现大量的胶原纤维;TS14组胸主动脉内皮细胞变性较明显,部分内皮细胞基质致密化,基膜复层化,内弹力板有破碎,弹力纤维增多。TS7组肺动脉部分内皮细胞突起,细胞内出现脂滴,内皮细胞基膜出现分层状改变,弹力板变薄、断裂,其下方可见收缩型平滑肌及合成型平滑肌细胞;TS14组肺动脉内皮细胞空泡变性较明显,内弹力板未见明显改变,弹力板内外均可见较多的胶原纤维和弹力纤维,内弹力板下方以收缩型平滑肌为主。结论TS7组大鼠胸主动脉和肺动脉出现损伤和增殖并存,以肺动脉较明显;TS14组肺动脉趋于形成新的稳定结构,而胸主动脉新稳定结构还未形成。模拟微重力时大小循环血管发生了结构重塑,大小循环血管重塑的时间过程不同归因于模拟微重力初期由下体转移而来的体液进入大小循环高峰期的时间差。     

实验性糖尿病肺iNOS和VIP免疫组织化学观察及图像分析

目的:探讨糖尿病大鼠肺诱生型一氧化氮合酶(iNOS)及血管活性肠肽(VIP)的病理变化。方法:采用免疫组织化学方法,观察正常和四氧嘧啶诱导的糖尿病4周大鼠肺内iNOS及VIP的变化,并进行图像分析。结果:糖尿病4周大鼠肺支气管上皮细胞、肺泡管上皮细胞、肺泡囊上皮细胞和动脉内皮细胞iNOS呈阳性或弱阳性,静脉内皮细胞、毛细血管内皮细胞iNOS呈阴性。图像分析表明,糖尿病鼠肺iNOS的着色面积、积分光密度和相对含量均明显低于正常大鼠肺。糖尿病4周鼠肺支气管纤毛上皮细胞VIP呈阳性,支气管平滑肌肌层、支气管粘膜下腺体周围、肺间隔和肺动脉壁外膜VIP呈弱阳性或阴性,图像分析显示糖尿病鼠肺VIP着色面积、积分光密度和相对含量均明显低于正常大鼠肺。结论:糖尿病肺病变不仅受自主神经影响,而且非肾上腺素能非胆碱能神经改变亦与之有关,其神经递质NO和VIP可能在糖尿病肺病变中具有重要意义。     

香烟烟雾暴露对大鼠肺组织Wnt3a和β-catenin蛋白表达的影响

目的 探讨香烟烟雾暴露对大鼠肺组织Wnt3a和β-catenin蛋白表达的影响.方法 20只雌性SD大鼠,按随机数字表分为对照组和模型组,每组10只.模型组大鼠被动吸入香烟烟雾,每天2次,每次45 min;对照组大鼠不接触香烟烟雾.100d后处死动物,光镜下观察肺组织的病理形态学改变,免疫组化法检测肺组织α-平滑肌肌动蛋白(α-SMA)、Wnt3a和β-catenin蛋白表达,并测定2组大鼠支气管平滑肌厚度.结果 模型组大鼠肺组织呈现慢性炎性反应和肺气肿样改变,小气道壁及平滑肌层增厚明显.α-SMA主要表达于气道和血管的平滑肌层.模型组支气管平滑肌厚度高于对照组[ (3.06±0.62) μm比(1.86±0.43) μm,P＜0.05].Wnt3a和β-catenin主要表达于支气管上皮细胞和肺泡上皮细胞.模型组与对照组支气管上皮细胞Wnt3a蛋白表达分别为74.54±4.14、89.24±3.02;肺泡上皮细胞Wnt3a蛋白表达分别为91.97±2.50、110.46±3.85,组间比较差异均有统计学意义(均P＜0.05).模型组与对照组支气管上皮细胞胞质β-catenin蛋白表达分别为86.97±4.87、103.18±3.77;支气管上皮细胞胞核β-catenin蛋白表达分别为95.75±3.91、116.12±5.76;肺泡上皮细胞胞质β-catenin蛋白表达分别为106.24±4.57、128.81±3.96;肺泡上皮细胞胞核β-catenin蛋白表达分别为125.44±4.89、152.90±4.10,组间比较差异均有统计学意义(均P＜0.05).结论 香烟烟雾可诱导大鼠肺组织Wnt3a和β-catenin蛋白表达上调.     

原发性高血压患者血清NO、NOS及其亚型水平的分析

目的:测定原发性高血压患者外周血中血清一氧化氮(NO)、一氧化氮合酶(NOS)及其亚型水平,探讨NO/NOS系统参与血压调节的可能机制.方法:原发性高血压患者135例,正常对照组35例.采用化学法检测所有病例外周血的一氧化氮(NO)、总NOS、诱导型一氧化氮合酶(iNOS)和结构型一氧化氮合酶(cNOS)水平并作统计学分析.结果:高血压组NO、NOS、iNOS和cNOS水平均低于正常对照组,且差异具有显著性意义(分别为:P＜0.05,P＜0.01,P＜0.01,P＜0.01);iNOS/cNOS比值与正常对照组相比无显著差异(P＞0.05);对照组和高血压组的NOS浓度与iNOS和cNOS浓度均呈显著正相关;高血压组的cNOS水平与iNOS水平呈显著负相关.结论:高血压患者NO、NOS及其亚型浓度值可以作为临床评估高血压的参考指标;iNOS在正常人体内有表达;在高血压情况下,机体有通过增加iNOS的表达来弥补cNOS水平的病理性降低、调控NOS总体水平从而调节和平衡血压的趋势.     

黄岑苷干预对输血相关急性肺损伤大鼠肺组织IL-1β、IL-10、TNF-α和iNOS表达的影响

目的探讨黄岑苷干预对输血相关急性肺损伤大鼠肺组织白细胞介素-10(IL-10)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)和诱导型一氧化氮合酶(iNOS)表达的影响。方法 SD大鼠45只,随机分为对照组、输血相关急性肺损伤组(TRALI)和黄岑苷干预组(造模前3d,每日经腹腔注射0.2ml的黄芩苷溶液,50mg/kg),每组15只。制模完成后处死大鼠,HE染色观察肺组织病理学改变,取支气管肺泡灌洗液(BALF)检测细胞总数、中性粒细胞比例;采用酶联免疫吸附试验(ELISA)测定各组大鼠支气管肺泡灌洗液中IL-10、IL-1β、TNF-α的含量。免疫组织化学与Western bolt检测大鼠肺组织中iNOS的表达。结果 TRALI组大鼠肺组织肺泡间隔增厚、肺间质充血及肺泡腔可见大量炎性细胞浸润,正常组大鼠肺组织结构清楚,肺泡壁结构完整,肺泡内未见炎性细胞渗出。TRALI组BALF细胞总数与中性粒细胞比例、IL-10、IL-1β与TNF-α的含量比正常组显著升高,给予黄岑苷干预后,则显著降低。TRALI组大鼠肺组织iNOS阳性表达水平显著升高,给予黄岑苷干预后,则显著降低。结论黄岑苷对输血相关急性肺损伤的保护作用与降低肺部炎性因子表达减轻炎性反应相关。     

Role of inducible nitric oxide synthase expressed by alveolar macrophages in High Mobility Group Box 1- induced acute lung injury

Objective and design The role of inducible nitric oxide synthase (iNOS) expressed by alveolar macrophages in acute lung injury induced by high mobility group box 1 (HMGB1) was explored. Treatments Primary rat alveolar macrophages (PRAMs) were stimulated with HMGB1 to analyze iNOS expression. Alveolar macrophages and iNOS were inhibited by gadolinium chloride and 1400W in rats challenged by HMGB1 intratracheally. Methods Western Blot was applied to assay iNOS expression in PRAMs. Indices for acute lung injury in rats were measured. Immunocytochemistry was used to localize iNOS in□bronchoalveolar lavage (BAL) cells. The enzyme activities of iNOS and constitutive nitric oxide synthase (cNOS) for BAL cells were determined. Results A time- and concentration-dependent response of iNOS expression in PRAMs to HMGB1 induction was observed. Intratracheal instillation of HMGB1 produced persistently exacerbated acute lung inflammation, induction of iNOS in alveolar macrophages and increased lung nitric oxide production in rats. Abrogation of iNOS or macrophages attenuated lung inflammation, nitric oxide in BAL fluid, and iNOS activity of BAL cells, but had no significant effect on cNOS activity of BAL cells in rats challenged by HMGB1. Conclusions Inducible nitric oxide synthase expressed by alveolar macrophages facilitates the development of HMGB1-induced acute lung injury. Received 12 March 2005; returned for revision 11 January 2006; accepted by M. Parnham 24 January 2006     

一氧化氮及一氧化氮合酶在急性吸入高浓度氧大鼠肺泡上皮细胞凋亡中的作用

目的: 观察一氧化氮及其合酶在急性吸入高浓度氧大鼠肺泡上皮细胞凋亡中的作用。方法: 60只大鼠随机分为空气对照组(21%O₂)和高氧实验组4 h组、8 h 组、12 h组和16 h组(85%~100%O₂),每组12只,雌雄各半。比色法测定血浆、肺组织匀浆中丙二醛(MDA)、一氧化氮(NO)和一氧化氮合酶(NOS)活性。Western blotting检测肺组织中eNOS和iNOS蛋白表达。采用TUNEL染色法检测肺泡表面凋亡细胞,HE染色观察肺组织病理改变。结果: 与对照组比较,高氧各时相组血浆及肺组织匀浆MDA、NO、NOS均升高,差异显著(P<0.01)。对照组eNOS明显表达,高氧4 h组表达开始升高,8 h组eNOS蛋白质表达升高明显。对照组iNOS蛋白微量表达,但表达量远低于eNOS,16 h组表达略增强。与对照组(2.17%±1.80%)比较,4 h组肺泡上皮细胞凋亡数量增加9.13%±3.20%,8 h组、12 h组及16 h组凋亡细胞的数量增加达17.47%±3.50%、19.22%±4.50%和11.03%±2.80%。高氧各组血浆及肺组织各指标与细胞凋亡呈明显的正相关。结论: NO及eNOS在急性高氧诱导的肺泡上皮细胞凋亡的过程中可能发挥介导作用。     

慢性低O2高CO2肺动脉高压大鼠血浆NO和肺动脉NOS及其基因表达的变化

目的：探讨一氧化氮体系在慢性低O₂高CO₂肺动脉高压形成中的作用。方法：雄性Sprague-Dawley大鼠分为正常对照组和4周低O₂高CO₂肺动脉高压组。测定血浆NO含量,免疫组化法检测肺细小动脉cNOS和iNOS活性,原位杂交法检测其cNOS mRNA和iNOS mRNA的表达。结果：肺动脉高压组血浆NO含量、肺细小动脉cNOS活性和cNOS mRNA表达显著低于对照组（均P<0.01）,而iNOS活性和iNOS mRNA表达明显高于对照组（均P<0.01）。结论：低O₂高CO₂时肺动脉NOS活性和NOS mRNA表达的改变引起的NO变化参与了肺动脉高压的形成。     

Cell-specific nitric oxide synthase-isoenzyme expression and regulation in response to endotoxin in intact rat lungs

Nitric oxide (NO) produced by NO synthase (NOS) serves as a ubiquitous mediator molecule involved in many physiologic lung functions, including regulation of vascular and bronchial tone, immunocompetence, and neuronal signaling. On the other hand, excessive and inappropriate NO synthesis in inflammation and sepsis has been implicated in vascular abnormalities and cell injury. At least three different NOS isoforms (neuronal/brain [bNOS], inducible [iNOS], and endothelial [eNOS]) have been described, which are all expressed in normal lung tissue. We investigated the cell-specific expression of bNOS, iNOS, and eNOS in perfused control rat lungs and lungs undergoing stimulation with endotoxin in the presence and absence of plasma constituents. Lung immunohistochemistry and quantitative evaluation of staining intensity showed endotoxin-induced increase in iNOS expression in particular in bronchial epithelial cells, cells of the bronchus-associated lymphoid tissue (BALT), alveolar macrophages, and vascular smooth muscle cells in a time- and dose-dependent fashion. In endothelial cells, which did not express iNOS at baseline, newly induced iNOS was found in response to endotoxin. In contrast, expression of eNOS was markedly suppressed under endotoxin challenge, particularly in bronchial epithelium, BALT, and alveolar macrophages but also in vascular smooth muscle cells and endothelial cells. eNOS expression in bronchial smooth muscle cells was not altered. In contrast to iNOS and eNOS, cellular expression of bNOS in epithelial cells, nerve fibers, BALT, and endothelial cells did not change in response to endotoxin. All changes in NOS regulation were found to be independent of plasma constituents. We conclude that endotoxin exerts a profound impact on the cell-specific NOS regulation in a large number of lung cell types. Prominent features include de novo synthesis or up-regulation of iNOS, in contrast to down-regulation of eNOS, which may well contribute to vascular abnormalities, inflammatory sequelae, and loss of physiologic functions in septic lung failure.     

内源性H2S对LPS所致大鼠急性肺损伤时肺动脉高压的影响及其与一氧化氮的相互作用

目的： 探讨硫化氢（H2S）对脂多糖（LPS）所致急性肺损伤时肺动脉高压（PAH）的影响及H2S/胱硫醚-γ-裂解酶（CSE）体系和一氧化氮（NO）/一氧化氮合酶（NOS）体系在其发生机制中的相互作用。 方法： 将72只大鼠随机分为生理盐水（NS）对照组、LPS组、LPS+L-NAME组、LPS+PPG组，检测给药后2、4、6、8 h的平均肺动脉压（mPAP），以及4、8 h血浆H2S、NO含量和iNOS、cNOS活性、肺组织NO含量和iNOS、cNOS、CSE活性，免疫组化法测定肺组织iNOS蛋白表达，并结合肺光镜形态等指标综合评价肺损伤程度。 结果： LPS组各时点的mPAP显著高于对照组，给药后4、8 h，NO含量、iNOS活性和蛋白表达升高，cNOS活性及H2S含量、CSE活性降低，肺组织损伤较重。预先给予L-NAME可减轻LPS所致上述指标的改变。而预先给予PPG可加重LPS所致肺损伤，但对cNOS活性无明显影响。 结论： LPS使内源性H2S减少导致mPAP升高； H2S/CSE体系与NO/NOS体系共同参与LPS所致急性肺损伤时PAH形成的调控机制，在其中呈相互的负性调节作用。     

氨基胍等对严重烧伤大鼠一氧化氮表达及烧伤休克的影响

目的:研究一氧化氮合酶(NOS)抑制剂与严重烧伤大鼠体内NO产量、NOS表达以及平均动脉压(MAP)变化的关系。方法:复制大鼠重症烧伤模型,检测应用非选择性NOS抑制剂L-NAME和选择性诱生型NOS(iNOS)抑制剂氨基胍(AG)后大鼠血液中NO代谢产物(NO₂^-／NO₃^-)以及肺和十二指肠组织中神经型NOS(nNOS)mRNA的表达水平,同时测定各组大鼠的MAP。结果:烧伤后大鼠血液中NO₂^-／NO₃^-含量显著增高,L-NAME和AG都能抑制NO₂^-／NO₃^-的升高,P<0.01;烧伤后nNOS的mRNA表达在肺和十二指肠中均有不同程度升高,AG和L-NAME使nNOS表达增加,L-NAME作用更为显著,P<0.01;烧伤后大鼠MAP略有上升,然后进行性下降,L-NAME组大鼠MAP显著升高,但于3h后急剧下降,AG组大鼠MAP下降速度明显低于对照组。结论:结构型NOS(cNOS)与iNOS在烧伤休克病理生理过程中的作用明显不同,iNOS活性过度增高与烧伤休克发病关系密切。     

The expression and activity of renal nitric oxide synthase and circulating nitric oxide in polycystic kidney disease rats

Nitric oxide (NO) influences tubular fluid and electrolyte transport, and hence possibly also fluid accumulation in renal cysts. The expression and activity of intrarenal constitutive NO synthase (cNOS) [neuronal NOS, nNOS and endothelial NOS, eNOS] and inducible NOS (iNOS) and plasma nitrite/nitrate (PNOx) concentration were assessed in homozygous Han:SPRD polycystic kidney disease (PKD) rats (cy/cy), heterozygous Han:SPRD PKD rats (cy/+), homozygous normal Han:SPRD littermates (+/+) and Sprague Dawley rats (sd). The results showed: 1) nNOS expression was decreased in proximal tubules and thick ascending limbs of the loop of Henle in cy/cy and cy/+ rats compared to +/+ and sd rats (p<0.05). nNOS was weakly expressed in the epithelium of small cysts and unexpressed in epithelium of large cysts. 2) iNOS expression was increased in proximal tubular epithelial cells in cy/+ rats compared to +/+ rats and sd rats (p<0.01). iNOS expression in cyst epithelium was decreased in cy/+ rats (p<0.05) and absent in cy/cy rats. 3) eNOS expression was similar in the endothelium of intrarenal arteries in all groups. 4) The activity of renal cNOS was decreased in cy/cy and cy/+ rats; the activity of iNOS was decreased only in cy/cy rats, with no significant difference among the other three groups. 5) PNOx concentration was higher in cy/cy rats than in the other three groups, and correlated positively with plasma creatinine and urea. In conclusion, NOS expression and activity decreased as cysts developed, suggesting that NO downregulation is involved in the pathogenesis of PKD.     

Myenteric denervation in gastric carcinogenesis: differential modulation of nitric oxide and annexin-A1

This study evaluated the properties of endogenous nitric oxide synthases (NOS) and annexin-A1 (ANXA1) and determined how they can be exploited in the N-methyl-N-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis and myenteric denervation model. Male Wistar rats were treated with MNNG and/or aminoguanidine (AG) for 20 weeks. In another set of experiments, rats with nondenervated and denervated stomachs were treated with MNNG or water for 28 weeks. Fragments of the pyloric region were processed for histopathology, NOS activity, and immunohistochemistry to explore the activity and expression of constitutive (cNOS) and inducible (iNOS) NO synthase and their relationship with annexin-A1 (ANXA1) expression. NO inhibition by AG increased the percentage of animals with adenocarcinomas (~29%) compared with the untreated MNNG group (~4%). Myenteric denervation did not alter NOS activity. cNOS activity was significantly greater in nondernervated and denervated stomachs with or without lesions (P<0.001) than iNOS activity (P<0.01), as confirmed by immunohistochemistry. Further, cNOS activity in normal stomachs and outside the lesion area was considerably higher than inside it (P<0.01). By densitometric analysis of nondenervated and denervated stomachs, ANXA1 expression was modulated in epithelial and inflammatory cells (mast cells and neutrophils), wherein significant alterations were induced by lesion development and myenteric denervation. In conclusion, NO protects against the development of gastric adenocarcinomas. The pattern of ANXA1 expression was not associated with NOS activity or expression, suggesting that NO and ANXA1 act in gastric tumors in disparate pathways.     

Effect of adenovirus-mediated gene transfer of nitric oxide synthase on vascular reactivity of rat isolated pulmonary arteries

Aerosol gene transfer of endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) to rat lungs increased NOS expression and activity, and prevented hypoxic pulmonary vasoconstriction (HPV) in vivo. Hereby, we examined the effect of eNOS and iNOS aerosol gene transfer on the endothelium-dependent relaxation (EDR) and on acute HPV in isolated rat pulmonary arteries. Changes in isometric forces were recorded in organ baths for large conduit arteries (diameter 1.8±0.1 mm) and in a wire myograph for small resistance arteries (258±35 μm). Male Wistar rats were randomly aerosolized with adenovirus (Ad) encoding β-galactosidase (control), eNOS, or iNOS. Four days later, exhaled nitric oxide was measured, NOS expression within rat lungs was evaluated by quantitative real-time polymerase chain reaction and immunohistochemistry, vasoconstricting agonist and acetylcholine concentration response curves were generated, and the time course of HPV was recorded. Human eNOS and murine iNOS were expressed within rat lung tissue mostly in parenchyma and endothelial cells. Large arteries isolated from Ad-i, eNOS-aerosolized rats developed lower agonist-induced tension than those of control rats. The first and second contractions of the HPV were smaller in the Ad-i, eNOS-aerosolized rats. Contractions were modestly, but significantly and inversely, related to exhaled NO. Agonist- and hypoxia-induced contractions were even more reduced after eNOS aerosolization. There was no significant effect on EDR and no notable difference between small and large vessels. We conclude that adenovirus (Ad)-mediated NOS gene transfer can counteract both pharmacologically and hypoxia-induced increases in pulmonary vascular tone in isolated rat pulmonary arteries. eNOS seems as efficient as iNOS in regulating pulmonary vascular tone.     

大鼠严重烧伤后体内一氧化氮水平变化与预后的关系

目的:研究一氧化氮(NO)及一氧化氮合酶(NOS)在严重烧伤早期大鼠体内的变化规律及其与预后的可能联系。方法:检测严重烧伤前后大鼠血液中NO代谢产物NO^-₂/NO^-₃及脑、肺脏和十二指肠组织中神经型(nNOS)和诱生型一氧化氮合酶(iNOS)蛋白的水平,同时统计各组大鼠的存活率。结果:烧伤后大鼠血液中NO^-₂/NO^-₃水平显著增高,非选择性NOS抑制剂L-NAME和选择性iNOS抑制剂氨基胍(AG)对其均有抑制作用,以L-NAME为甚;nNOS蛋白在伤后部分升高,L-NAME和AG均轻度上调nNOS水平;iNOS在正常组织中不表达,烧伤后表达异常增高,L-NAME和AG对此均无影响;与对照组比较,AG组大鼠存活时间延长,L-NAME组存活时间缩短。结论:严重烧伤后的血管扩张、血压降低和血管反应性低下与iNOS蛋白水平过度增高及其释放的大量NO关系密切。