自制复方中药对局灶性脑缺血大鼠脑组织一氧化氮含量的影响

目的:动态观察自制复方中药对局灶性脑缺血大鼠脑梗死体积和脑组织一氧化氮含量的影响,并与步长脑心通药物进行对照.方法:实验于2004-09/12在河北医科大学中医学院完成.将176只SD大鼠随机分为5组,①假手术组:只分离、暴露血管,不结扎颈总动脉及颈外动脉,不插入尼龙鱼线,5g/L羧甲基纤维素钠液灌胃.②模型组:采用线栓法复制局灶性脑缺血大鼠模型,5g/L羧甲基纤维素钠液灌胃.③中风康1.88g/mL组:制备局灶性脑缺血大鼠模型,18.8 g/kg中风康灌胃(由枸杞子、怀牛膝、川芎、水蛭、地龙、橘络、胆南星、石菖蒲、冰片等药物组成).④中风康0.94 g/mL组:制备局灶性脑缺血大鼠模型,0.94g/kg中风康灌胃.⑤步长脑心通组:制备局灶性脑缺血大鼠模型,0.33g/kg步长脑心通灌胃.假手术组每时间点取8只大鼠,其余各组每时间点取9只大鼠,于脑缺血6,12,24,48 h动态观察各组大鼠脑梗死体积和脑组织一氧化氮含量.结果:模型组,中风康1.88g/mL组,步长脑心通组,中风康0.94g/mL组分别死亡1,2,2,3只,造模失败3,2,2,1只,进入结果分析数量为每组大鼠32只,每时间点各8只.①各组大鼠脑梗死体积:局灶性脑缺血6 h模型组梗死灶体积迅速扩大,随缺血时间延长,梗死灶体积缓慢进展,24 h达到高峰,至48 h梗死灶略有缩小;各治疗组梗死灶体积均有不同程度缩小,以中风康1.88 g,/mL组效果最为显著(P＜0.05或P＜0.01),且缺血6 h中风康1.88g/mL组梗死灶体积明显小于步长脑心通组[(88±31),(136±35)mm2,(p＜0.01)].②各组大鼠脑组织一氧化氮含量;局灶性脑缺血6 h,模型组脑组织一氧化氮含量开始升高,24 h达到高峰;局灶性脑缺血24 h和48 h,中风康1.88 g/mL组一氧化氮含量明显低于模型组[(20.69±3.52),(24.89±3.13)μmol/g;(17.15±4.07),(22.37±3.04)μmol/g,(P＜0.05或P＜0.01)],局灶性脑缺血48 h,步长脑心通组一氧化氮含量亦明显低于模型组[(1827±3.35),(22.37±3.04)μmol/g,(P＜0.05)].结论:中风康可通过降低脑组织一氧化氮含量,减轻细胞毒作用,缩小梗死灶体积,能有效的减轻局灶性脑梗死引起的缺血性损伤,其疗效优于步长脑心通.     

"手十二井穴"刺络放血对大鼠局灶性脑缺血后一氧化氮合酶活性的干预作用

背景:“手十二井穴”刺络放血疗法是治疗脑卒中的一种有效急救方法,动物实验证明“手十二井穴”刺络放血具有扩张脑血管,增加脑血流量,改善缺血区脑组织的急性缺氧状态,缓解乳酸堆积造成的酸中毒等作用。目的:探讨“手十二井穴”刺络放血对大鼠脑缺血后一氧化氮含量和一氧化氮合酶活性变化的影响及机制。设计:随机对照动物实验。单位:咸宁学院医学院生理教研室。材料:实验于2003-03/2004-02在咸宁学院医学院生理教研室完成。实验选用84只Wistar大鼠,鼠龄二三个月,雌雄兼用,体质量(230±20)g,由咸宁学院医学院实验动物中心提供。方法:将84只大鼠随机分为假手术组、缺血组、缺血 刺络放血组,每组28只。采用改良Longa法犤3犦制作大鼠大脑中动脉栓塞模型,缺血 刺络放血组在脑缺血后立即用三棱针按少商,商阳,中冲,关冲,少冲,少泽的顺序,先左前肢,后右前肢,点刺相当于人的“手十二井穴”解剖位置,使出一滴血,以不下滴为度。各组分别在缺血30min,1,2,4h取脑组织,测定一氧化氮含量和一氧化氮合酶活性。主要观察指标:各组大鼠脑组织一氧化氮含量和一氧化氮合酶活性。结果:①缺血组大鼠在缺血30min,1,2,4h一氧化氮含量分别为(116.16±26.63),(118.94±24.47),(115.65±25.29),(108.87±26.52)μmol/L,一氧化氮合酶活性分别为(507.22±92.52),(502.08±92.52),(510.71±96.63),(495.29±88.41)μkat/L,显著高于假手术组(t=2.474～4.731,P<0.05～0.001)。②缺血 刺络放血组一氧化氮含量分别为(91.8±11.51),(93.55±13.88),(92.52±11.62),(84.3±11.51)μmol/L,一氧化氮合酶活性分别为(337.6±88.41),(340.99±96.63),(344.48±84.3),(337.6±90.46)μkat/L,与缺血组比较差异有显著性意义(t=2,199～3.507,P<0.05～0.01)。结论:“手十二井穴”刺络放血可抑制脑缺血后脑组织一氧化氮含量,一氧化氮合酶活性升高,减轻自由基对脑组织损伤,从而对大鼠局灶性脑缺血有保护作用。     

高压氧对大鼠脑缺血再灌注损伤后一氧化氮合酶阳性细胞分布和形态的影响

背景:一氧化氮在脑缺血损伤中起着很重要的作用,而高压氧能改善缺血再灌注引起的神经损伤,高压氧的这种作用与一氧化氮是否有关联?其机制有待探讨。目的:观察一氧化氮合酶阳性细胞在大鼠急性局灶性脑缺血再灌注损伤和高压氧治疗后表达的变化。设计:随机对照动物实验。单位:解放军第四军医大学唐都医院急诊科;西安高新医院检验中心;解放军空军总医院。材料:取健康SD雄性大鼠66只,随机分为5组:假手术组5只,假手术 高压氧组5只,模型组28只,模型 高压氧组28只,后2组又分缺血后5,12,24,72h4个时间点,每个时间点7只。方法:①造模:模型组和模型 高压氧组大鼠参照Koizum方法制备大脑中动脉缺血模型,并于插入栓子造成缺血1h后抽出栓子。其他2组手术,但不插入栓子。②高压氧治疗:假手术 高压氧组和模型 高压氧组大鼠分别在缺血后2,9,21,45,69h共5次将动物置于高压氧舱内,给予高压氧(0.25MPa绝对压)治疗1h。主要观察指标:各组于相应时间点处死取脑,黄递酶-NADPH组织化学方法观察一氧化氮合酶阳性细胞在视交叉平面梗死区皮质、视前区、纹状体外侧区和纹状体内侧区域分布及形态的变化。结果:经补充后66只大鼠进入结果分析。①缺血后一氧化氮合酶阳性细胞发生形态改变,主要变化为突起减少或消失,细胞由椭圆形、三角形变成圆形,细胞皱缩,胞体着色重,胞核和胞浆均染成深蓝色;形态改变的一氧化氮合酶阳性细胞在纹状体外侧区最多,其次是视前区和纹状体内侧区,而皮质区较少。假手术组和假手术 高压氧组未见有形态改变的一氧化氮合酶阳性细胞。②模型组脑内形态有改变的一氧化氮合酶阳性细胞表达随缺血再灌注时间延长而增多,模型 高压氧组各时间点在皮质、视前区和纹状体内侧区其表达均比模型组少,但都于缺血后72h至高峰[皮质:(15.46±3.02),(30.52±4.73)个/视野;视前区:(28.56±4.05),(68.81±7.84)个/视野;纹状体内侧区:(21.09±3.83),(45.71±5.24)个/视野;P均<0.01]。结论:高压氧可明显抑制大鼠急性局灶性脑缺血再灌注损伤区一氧化氮合酶阳性细胞的变性,部位主要在皮质、视前区和纹状体内侧区。     

不同剂量脑醒喷鼻剂对再灌注损伤脑组织自由基及一氧化氮合酶变化的干预

背景脑醒喷鼻剂由川芎和石菖蒲等中药组成,<神农本草经>谓其"主脑卒中入脑"之功效.目的观察脑醒喷鼻剂对大鼠局灶性脑缺血再灌注损伤脑组织自由基及一氧化氮合酶变化的影响,并与经典西药尼莫地平相比较.设计随机对照实验.单位一所中医药大学医院的内科.对象清洁级成年雄性Wistar大鼠70只,随机分为7组脑醒喷鼻剂高剂量组(高剂组),脑醒喷鼻剂中剂量组(中剂组),脑醒喷鼻剂低剂量组(低剂组),尼莫地平腹腔注射组(尼莫地平组),生理盐水喷鼻剂组(生理盐水组),溶酶喷鼻剂组(溶酶组),假手术组,每组10只.方法除假手术组外,其他6组阻断大鼠左侧大脑中动脉建立大鼠局灶脑缺血再灌注模型.在造模前3 d及再灌注期间,脑醒喷鼻剂高、中、低剂组分别以含川芎嗪和石菖蒲生药5.4,2.7,1.08 mg/(kg·d)和1 35,0.54,0.27g/(kg·d)的剂量滴鼻,3次/d;生理盐水组和溶酶组以生理盐水、溶酶喷鼻剂0.18 mL/(kg·d)滴鼻,3次/d;尼莫地平组用尼莫地平注射液0.8 mg/(kg·d)腹腔注射,2次/d;假手术组按常规饲养至实验取材.用比色法检测丙二醛、超氧化物歧化酶及一氧化氮合酶.主要观察指标①不同剂量脑醒喷鼻剂及其他组动物脑组织丙二醛、超氧化物歧化酶及一氧化氮合酶活性变化.②将不同剂量脑醒喷鼻剂组与尼莫地平组做比较.结果造模时死亡8只动物,进入结果分析62只.①丙二醛含量高剂组、尼莫地平组明显低于生理盐水组[(0.92±0.32),(0.87±0.39),(1.35±0.34)μmol/g,P＜0.05],但高剂组和尼莫地平组间无差异.②超氧化物歧化酶活性高剂组、尼莫地平组明显高于生理盐水组[(35.64±11.67),(33.88±7.15),(20.70±3.88)NU/mg,P＜0.05],但高剂组和尼莫地平组间无差异.③一氧化氮合酶活性及超氧化物歧化酶活性高剂组、尼莫地平组明显高于生理盐水组[(4.64±1.22),(5.00±1.10),(3.08±1.12)mkat/g,P＜0.05],但高剂组和尼莫地平组间无差异.④中、低剂组和溶酶组超氧化物歧化酶及一氧化氮合酶活性有所升高,丙二醛含量有所降低,但与生理盐水组比较无差异.结论脑醒喷鼻剂高剂量组能防止脑缺血缺氧所致的脂质过氧化,使丙二醛生成减少,清除自由基损害,并增加一氧化氮合酶活性,对脑组织的缺血再灌注损伤有保护作用,与尼莫地平的作用相当.     

黄芪对急性脑损伤后一氧化氮合酶活性的抑制作用

背景黄芪在机体免疫功能调节中具有重要作用,而在对急性颅脑损伤干预中是否具有神经元保护作用,且其发挥作用的途径何在?目的观察黄芪对脑损伤后脑组织一氧化氮合酶活性的影响.设计随机对照的实验.单位兰州军区神经外科研究所.对象实验于2001-09/12在兰州军区神经外科研究所实验室完成.取健康雄性SD大鼠54只,随机分为3组脑损伤组(n=24),黄芪组(n=24),对照组(n=6),损伤组与黄芪组均分为伤后0.5,2,6和24 h4个时间点,每个时间点6只动物.方法脑损伤组和黄芪组制备脑损伤模型,对照组仅开骨窗,不致伤.黄芪组致伤后立即腹腔注射黄芪200 mg/kg,用化学定量法检测大鼠脑损伤后不同时间点脑组织中一氧化氮合酶的活性.主要观察指标各组大鼠脑组织中一氧化氮合酶活性.结果54只大鼠全部进入结果分析.脑损伤组、黄芪组大鼠在伤后0.5 h一氧化氮合酶活性较对照组升高[46.44±13.45)(43.15±12.43),(40.46±12 85)nkat/L,P＜0.05],伤后2 h达高峰[(67.49±22.45),(64.26±19.78)nkat/L,P＜0.01],伤后6 h开始下降[(63.46±24.68),(52.91±21.36)nkat/L,P＜0.01],伤后24 h降至基础水平[(41.23±12.57),(40.92±12.25)nkat/L,P＞0.05].黄芪组在伤后2,6 h一氧化氮合酶活性较损伤组明显降低(P＜0.01,0.05).结论颅脑损伤后,受损脑组织中一氧化氮合酶活性呈节段性升高,黄芪可通过抑制损伤后脑组织中一氧化氮合酶活性,起到保护创伤神经元的作用.     

大鼠局灶性脑缺血再灌注后脑组织的氧化损伤

目的:通过观察大鼠局灶性脑缺血再灌注后脑组织超氧化物歧化酶活性和丙二醛含量的变化,进一步探讨大鼠局灶性脑缺血再灌注后氧化损伤的病理生理改变。方法:实验于2004-09/2005-01在泸州医学院神经生物学教研室进行。将雄性成年Wistar大鼠60只随机分为2组:假手术组30只和缺血再灌注组30只。每组分3个观察时间点,分别为手术后6,12,24h,每个时间点10只。采用线栓法制成大脑中动脉闭塞模型,假手术组手术过程同缺血再灌注组,但未插栓线,不造成脑缺血。测定手术后不同时点脑组织超氧化物歧化酶活性和丙二醛水平。结果:在实验过程中有6只大鼠死亡,缺血再灌注组有8只大鼠手术后模型评价为0级,被排除实验,随机补充14只大鼠,最终进入结果分析仍为60只大鼠。①缺血再灌注组术后6,12,24h超氧化物歧化酶活性均低于假手术组眼(289.72±10.67),(534.77±22.67)μkat/L;(330.57±18.17),(539.11±11.50)μkat/L;(377.58±14.67),(550.78±11.50)μkat/L,P<0.05演。②缺血再灌注组术后6,12,24h丙二醛水平显著高于假手术组眼(15.06±0.59),(6.78±0.25)μmol/L;(13.53±1.11),(6.78±0.26)μmol/L;(11.31±0.97),(6.80±0.26)μmol/L,P<0.05演。结论:脑缺血再灌注后,缺血大鼠脑组织内丙二醛水平升高,超氧化物歧化酶活性降低,说明自由基参与了脑缺血再灌注损伤的病理生理过程。     

丹参酮ⅡA对鼠脑缺血再灌注损伤一氧化氮及一氧化氮合酶的影响

目的 探讨丹参酮ⅡA(Tan ⅡA)对脑缺血再灌注损伤大鼠脑组织及血清中一氧化氮(NO)含量、一氧化氮合酶(NOS)及诱导型一氧化氮合酶(iNOS)活性的影响.方法 40只Wistar大鼠随机分为假手术组、缺血再灌注组、Tan Ⅱ A低剂量治疗组和TanⅡA高剂量治疗组,线栓法建立局灶性脑缺血再灌注模型.Tan Ⅱ A高、低剂量治疗组于术前连续灌胃给予高、低剂量Tan Ⅱ A 3 d,每天1次.各组于脑缺血90 min再灌注24 h进行HE染色观察病理形态学变化,检测脑组织和血清中NO含量和NOS、iNOS活性.结果 Tan Ⅱ A高、低剂量治疗组脑组织缺血损伤病理学改变轻于缺血再灌注组,Tan ⅡA高剂量治疗组缺血改变轻于低剂量治疗组.与假手术组比较,缺血再灌注组脑组织和血清中NO含量和NOS、iNOS活性明显升高;与缺血再灌注组比较,Tan Ⅱ A高、低剂量治疗组脑组织和血清中NO含量和NOS、iNOS活性均降低,高、低剂量组之间有显著性差异(P《0.05).结论 Tan Ⅱ A可减轻神经元损伤程度,对缺血再灌注脑损伤具有保护作用,其机制可能与可降低NOS、iNOS活性,减少NO含量有关.     

异丙酚预处理对全脑缺血再灌注大鼠脑损伤和神经行为学的影响

目的:观察异丙酚预处理对全脑缺血再灌注大鼠脑组织S100B及神经元特异性烯醇化酶含量的影响,分析异丙酚的脑保护作用。方法:实验于2005-03/05在解放军广州军区武汉总医院动物实验中心完成,36只雄性SD大鼠,随机分为假手术组、脑缺血模型组和异丙酚预处理组,每组12只,异丙酚预处理组动物在缺血前腹腔注射异丙酚100mg/kg,采用线栓法制作全脑缺血模型,假手术组同样麻醉手术但不行颈总动脉夹闭术,脑缺血模型组麻醉后采用线栓法制作全脑缺血模型,3组动物于脑缺血再灌注后24h评估并记录动物的神经行为学评分,取大鼠脑组织行S100B和神经元特异性烯醇化酶测定。结果:36只大鼠顺利完成全部实验的有34只。脑缺血再灌注组和异丙酚预处理组各有1只动物在脑缺血再灌注后出现偏瘫无法进行余下实验,这可能与动物的个体差异不能耐受实验有关,随机取30例作为结果分析样本(每组10只)。①假手术组和异丙酚预处理组旷场评分、斜坡实验、悬挂时间评分均较脑缺血模型组高[(29.75±4.17),(24.25±7.51),(10.13±3.22)格;(8.13±2.36),(8.50±3.48),(16.25±3.79)s;(51.00±5.93),(32.75±6.13),(13.13±4.25)s;P<0.05～0.01];异丙酚预处理组悬挂时间评分较假手术组低(P<0.05),旷场评分和斜坡实验评分也低于假手术组,但差异无显著性意义(P>0.05)。②假手术组和异丙酚预处理组脑组织中S100B和神经元特异性烯醇化酶含量均明显低于脑缺血模型组[(0.35±0.07),(0.83±0.47),(1.47±0.88)μg/L;(4.35±1.24),(10.40±5.66),(19.68±9.73)μg/L;P<0.05～0.01]。假手术组和异丙酚预处理组比较差异有显著性意义(P<0.05)。结论:缺血前2h异丙酚预处理可以改善大鼠脑缺血再灌注损伤后的神经行为学评分,降低脑缺血损伤大鼠脑组织S100B及神经元特异性烯醇化酶的含量,减轻神经损害,有明显的脑保护作用。     

一氧化氮对大鼠局灶性脑缺血再灌注所致神经细胞损伤的影响

目的:观察应用硝普钠和一氧化氮合酶(NOS)抑制剂L-NAME对大鼠局灶性脑缺血再灌注所致神经细胞损伤的影响。方法:取SD大鼠44只,按随机数字表法分为4组:假手术组,脑缺血再灌注组,脑缺血再灌注加侧脑室微量注射L-NAME组,脑缺血再灌注加侧脑室微量注射硝普钠组。用栓线法复制大鼠大脑中动脉脑缺血再灌注模型,自颈内、外动脉分叉处起始,假手术组的尼龙栓子插入13mm,其余3组插入(18.0±0.5)mm造成大脑中动脉完全缺血30min,缓慢拔出尼龙栓子形成再灌注状态,L-NAME组和硝普钠组侧脑室微量注射L-NAME和硝普钠进行干预,假手术组和脑缺血再灌注组侧脑室注射等量生理盐水。于再灌注术后12,24h,2,4d分别处死动物取材,紫外分光光度计检测各脑组织一氧化氮含量,免疫组化法测脑组织NOS活性,TUNEL法检测调亡细胞。结果:脑缺血再灌注急性期(术后12h),脑组织一氧化氮含量迅速增高犤(10.14±1.97)mol/g犦,L-NAME明显降低脑组织一氧化氮的含量犤(3.86±1.35)mol/g犦,硝普钠能明显增加脑组织一氧化氮的含量犤(12.46±1.57)mol/g犦,SPSS10.0统计分析软件LSD法统计结果,各组间比较,F=24.07,P<0.05,有明显显著性意义。术后12hL-NAME抑制NOS的活性犤(16.0±1.2)个/视野犦,硝普钠组NOS的表达增强犤(62.0±4.2)个/视野犦,组间比较,F=     

诱导型一氧化氮合酶在关节软骨缺血再灌注损伤及软骨细胞凋亡中的作用

目的:观察兔膝关节软骨缺血再灌注损伤过程中诱导型一氧化氮合酶的表达规律及软骨细胞的凋亡情况,探讨诱导型一氧化氮合酶在关节软骨缺血再灌注损伤中的作用。方法:实验于2004-03/09在泰山医学院形态学研究室完成。①选择健康新西兰白兔45只,随机分为假手术组5只,暴露股动静脉但不阻断血运,术后4h取材;缺血组5只,缺血4h不恢复血运即取材;缺血再灌注组35只,阻断股动静脉4h后恢复血运,于缺血再灌注2,4,8,24h,3,7,14d取材,每时点各5只。②采用免疫荧光法测定软骨内诱导型一氧化氮合酶的表达阳性细胞,染色成功后用激光共聚焦显微镜观察并扫描记录。阳性细胞标记为红色荧光。③采用原位末端标记法测定凋亡软骨细胞数目,染色成功后在显微镜下观察并记数。细胞核中有棕黄色颗粒者为阳性细胞,即凋亡细胞。结果:纳入动物45只,均进入结果分析。①缺血再灌注组诱导型一氧化氮合酶阳性细胞数高于缺血组和假手术组[假手术组、缺血组、缺血再灌注2,4,8,24h,3,7,14d分别为0,(1.20±0.40),(22.20±1.30),(33.00±1.58),(40.00±1.58),(33.80±1.30),(18.20±1.48),(11.20±1.67),(3.00±1.00)个/mm2,P<0.01]。②缺血再灌注组软骨细胞凋亡数高于缺血组和假手术组[假手术组、缺血组、缺血再灌注2,4,8,24h,3,7,14d分别为[(0.50±0.40),(1.20±0.45),(7.80±1.30),(12.60±1.14),(16.60±1.12),(17.80±1.30),(15.20±0.87),(13.60±0.89),(4.40±1.67)个/mm2,P<0.01]。③诱导型一氧化氮合酶的表达与软骨细胞凋亡数高度相关(r=0.716,P=0.046)。结论:诱导型一氧化氮合酶参与了软骨缺血再灌注损伤,并可能是触发软骨细胞凋亡的重要因素。     

Exhaled nitric oxide

We introduce the standard method of measurement of nitric oxide recommended by American thoracic society in 1999 and report the results of exhaled NO and nasal NO in patients with obstructive sleep apnea syndrome(OSAS). Our data showed lower exhaled NO output in the patients with OSAS than that of normal volunteers(NV) and that of patients with simple obesity(SO). On the other hand, nasal NO in the OSAS patients is higher than that of NV and that of SO patients. Also, there were significant relationships between apnea index and exhaled NO and between desaturation during sleep and nasal NO. These findings suggested that NO from lower and upper airway will be a non-invasive maker of sleep disordered breathing in future.     

Modulation of nitric oxide synthase by nitric oxide donor compounds in migraine

A controlled study was performed to assess the involvement of the nitric oxide pathway in migraine pathophysiology. Thirteen patients with migraine without aura and seven clinically healthy subjects (C) were selected. All of the migraine patients were studied both before, during an asymptomatic phase (t ₀), and 1 h after the administration of 5 mg isosorbide dinitrate, a nitric oxide donor able to induce an experimental migraine attack (t ₁). The nitric oxide levels were analyzed as nitrite accumulation in serum samples, in peripheral blood mononuclear cell extracts, and culture supernatants. Basal nitrite levels in serum samples and peripheral blood mononuclear cell culture supernatants of migraine patients and healthy subjects indicated that migraine patients possess an activated nitric oxide synthesis pathway (t ₀ vs. C F=8.16,P<0.01 and F=16.2,P<0.01, respectively). As expected, in the migraine patients treated with the nitric oxide donor, a marked increase of nitrite levels was observed in sera (t ₁ vs.t ₀ P<0.05,t=3.05). In contrast, during the nitric oxide donor-induced migraine attacks a statistically significant decrease of nitrite levels in peripheral blood mononuclear cell culture supernatants was observed (t ₁ vs.t ₀ P<0.01,t=−4.03), whereas a significant increase of nitrite in total cell extracts was detected (t ₁ vs.t ₀ P<0.001,t=−6.89). These preliminary data suggest that nitric oxide could be involved in the neurovascular modifications leading to a migraine attack.     

Exogenous nitric oxide regulates activity and synthesis of vascular endothelial nitric oxide synthase

Background Nitric oxide (NO) – a major signalling molecule of the vascular system – is constitutively produced in endothelial cells (EC) by the endothelial NO synthase (eNOS). Since a reduced NO synthesis is an early sign of endothelial dysfunction and NO delivering drugs are used to substitute the impaired endothelial NO production, we addressed the effect of exogenous NO on eNOS in human umbilical venous endothelial cell cultures. Materials and methods The synthetic NO donor DETA/NO (trade name, but in the following we refer to detNO), that releases NO in a strictly first order reaction with a half life of 20 h, was used in our experiments. Results Short‐term (20–30 min) detNO treatment of EC increases the Ser¹¹⁷⁷ phosphorylation of the constitutively expressed endothelial NOS and the production of endogenous NO generated by eNOS from [³H]arginine. The phosphorylation of eNOS is Akt‐dependent and completely reverted by the phosphatidylinositol‐3 kinase (PI‐3K) inhibitor LY294002. A prolonged continuous exposure of EC to detNO 150 µmol L^?1 over a period of 24–48 h causes a reversible cell cycle arrest at G₁‐phase associated with a larger cell volume and increased cell protein content (hypertrophic phenotype of EC). The eNOS protein and mRNA of the hypertrophic cells and the generation of endogenous NO are reduced but eNOS phosphorylation could still be elevated by stimulation with vascular endothelial growth factor. Conclusions Our data explain clinical studies describing a short‐term but not a long‐term benefit of NO treatment for patients with cardiovascular risk factors. The results could be a rational approach to develop a generation of NO donors accomplishing a retarded release from NO donors that mimic the low continuous pulsatile stress‐induced release of endogenous NO.     

Inhaled nitric oxide down-regulates intrapulmonary nitric oxide production in lipopolysaccharide-induced acute lung injury

OBJECTIVE: To examine whether inhaled nitric oxide (NO) affected the intrapulmonary production of NO, reactive oxygen species, and nuclear factor-kappaB in a lipopolysaccharide (LPS)-induced model of acute lung injury. DESIGN: Prospective, randomized, laboratory study. SETTING: Experimental laboratory at a biomedical institute. SUBJECTS: Twenty male rabbits weighing 2.5-3.5 kg. INTERVENTIONS: Saline or LPS (5 mg/kg of body weight) was administered intravenously with or without NO inhalation (10 ppm) in each group of five rabbits. MEASUREMENTS AND MAIN RESULTS: LPS increased the lung leak index, the neutrophils and NO levels in bronchoalveolar lavage fluid, and NO levels produced by resting and stimulated alveolar macrophages. Inhaled NO decreased the lung leak index, the neutrophils and NO levels as measured by nitrite levels in the lavage fluid, and NO produced by the resting and stimulated alveolar macrophages. Inhaled NO also blocked the activities of reactive oxygen species and nuclear factor-kappaB binding to DNA in lavage cells and in alveolar macrophages. CONCLUSION: Inhaled NO attenuates LPS-induced acute lung injury, possibly by decreasing NO production in the lungs. The mechanism of reducing NO production resulting from inhaled NO may involve, in part, the activities of reactive oxygen species and/or nuclear factor-kappaB.     

大鼠小肠移植术后血清一氧化氮及小肠组织一氧化氮合酶和诱导型一氧化氮合酶活性的变化

目的:研究同种大鼠小肠移植后内源性一氧化氮、一氧化氮合酶(nitricoxidesynthase,NOS)及诱导型一氧化氮合酶(induciblenitricoxidesyn-thase,iNOS)的变化及一氧化氮与急性排斥反应的关系。方法:以大鼠小肠移植为研究对象,16只SD大鼠进行同系移植作为对照组,8只SD大鼠和8只Wistar大鼠进行同种移植作为实验组,两组移植后分别于第3,5,7天同时取血液及小肠组织,病理为常规苏木精-伊红染色观察,血清一氧化氮采用硝酸还原酶法测定,NOS和iNOS采用分光光度法测定。结果:在急性排斥反应发生的早期实验组血清一氧化氮水平与对照组比较显著升高(术后第3,5,7天t值分别为9.7900,9.0073,6.3159,P<0.01),小肠组织NOS及iNOS活性亦显著高于对照组(NOS术后第3,5,7天t值分别为5.9318,9.1237,3.0457,iNOS术后第3,5,7天t值分别为3.2008,5.4930,4.8170,P<0.01)。结论:大鼠小肠移植后NOS及iNOS变化与排斥反应相关,血清一氧化氮水平的检测可作为干预移植措施始动的指标之一。     

The role of nitric oxide synthase/nitric oxide in vascular smooth muscle control

Vascular compliance is dependent on endogenous and exogenous sources of nitric oxide (NO). In a discussion of therapeutics and NO derived via nitric oxide synthase (NOS) enzymes, it is necessary to examine the pathways of each drug to provide the clinical perfusionist with a greater understanding of the role of NOS/NO in vascular function. Endothelial-derived NO is a contributor in the vasoregulation of vascular smooth muscle. Therapeutics seek to mimic the vasodilatory effects of the endogenous NO. The therapeutics included in this review are nitroglycerin, nitroprusside, amyl nitrite, and inhalation of NO. L-Arginine supplementation provides additional substrate for the endogenous pathway that can augment NO production. NO is a small bioactive molecule involved in various biochemical pathways. Dysregulation of NO production can impair normal physiologic control of vascular compliance. Therefore, the purpose of this review is to provide the perfusionist with an understanding of the biochemical and pharmacological aspects of NOS/NO associated with vascular function.     

大鼠创伤性脑水肿一氧化氮及其合成酶的变化

目的：探讨脑损伤后一氧化氮（ＮＯ）及一氧化氮合酶（ＮＯＳ）与脑水肿的关系。方法：建立大鼠创伤性脑水肿模型,按不同时间点处死动物,测定其脑含水量及静脉血ＮＯ 和脑组织中ＮＯＳ。结果：脑创伤后脑含水量随静脉血ＮＯ的增加而增加,组织ＮＯＳ则随ＮＯ 的增加而下降。结论：创伤性脑水肿与血ＮＯ 有密切相关性,组织中ＮＯＳ则是该过程的可能催化剂     

Exhaled nitric oxide as a marker for serum nitric oxide concentration in acute endotoxemia

The main aim of this study was to assess the correlation between exhaled nitric oxide (NO) and serum NO concentrations during the course of endotoxemia. We also assessed whether or not the inducible isoform of NO synthase is responsible for the increase in NO production in endotoxemia animals.

Anesthetized and mechanically ventilated dogs were injected with either saline (control) or Escherichia coli endotoxin (LPS [Lipopolysaccharides]), and the animals were sacrificed 150 minutes later. We measured hemodynamics, exhaled NO, and serum arterial and mixed venous NO concentrations. Western blotting was performed on lung, pulmonary artery, aorta, and kidney tissue samples using anti-inducible NO synthase antibody.

Arterial pressure, cardiac output, and pulmonary arterial pressure in the control group remained unchanged, whereas a significant decline in these parameters was observed in the LPS group. Exhaled NO and serum arterial NO concentrations rose significantly within 30 minutes of endotoxin injection and remained higher than baseline values, whereas mixed venous serum NO did not change from baseline values. There was a significant linear relationship between exhaled NO and arterial serum NO concentrations. By comparison, exhaled NO, and arterial and mixed venous serum NO levels remained unchanged in the control group. Western blotting showed no expression of inducible NO synthase (iNOS) isoform in the control or LPS groups.

These results suggest that exhaled NO accurately reflects changes in arterial serum NO concentration and that the source of enhanced NO release in acute endotoxemia is not the iNOS isoform.