缺血预处理和缺血后处理对肾缺血-再灌注大鼠一氧化氮系统的影响

目的 探讨肾缺血预处理和缺血后处理对肾缺血-再灌注(I-R)损伤的影响机制.方法 SD大鼠50只均分为假手术组(A组)、I-R(B组)、缺血预处理组(C组)、缺血后处理组(D组)和联合处理组(E组).缺血45 rin再灌注24 h后取肾,检测一氧化氮(NO)含量、一氧化氮合酶(NOS)活性、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量;HE染色观察肾组织病理变化情况,并进行中性粒细胞(PMN)计数和Paller's评分;TUNEL法观察肾组织细胞凋亡情况.结果 与B组比较,C、D、E组的SCr、BUN显著降低、肾组织MDA含量显著减少、肾组织SOD活性和肾NOS、NO水平显著增加、肾小管上皮细胞阳性凋亡率显著降低(P＜0.01).结论 缺血预处理和缺血后处理均能够减轻肾I-R损伤,可能与其增加NOS在肾脏的表达有关.     

氨氯地平对高胆固醇大鼠心肌缺血再灌注时一氧化氮合酶的影响

目的 :探讨高胆固醇血症大鼠心肌缺血 再灌注损伤时氨氯地平对内皮型一氧化氮合酶 (eNOS)和诱导型一氧化氮合酶 (iNOS)在冠脉血管内皮表达的影响。方法 :雄性Wistar大鼠分 4组 :单纯高胆固醇血症组 ;氨氯地平组 ;氨氯地平 N 甲基亚硝基左旋精氨酸甲酯组 ;氨氯地平 假手术组。大鼠经高胆固醇喂养 6周后 ,开胸结扎左冠状动脉 ,缺血30min后 ,行再灌注 2 0min、2h。分别用免疫组织化学ABC法检测冠脉血管内皮eNOS和iNOS的表达水平。结果 :缺血前 ,氨氯地平可显著降低冠脉血管内皮iNOS表达 (P <0 .0 1)。缺血 30min ,高胆固醇血症组eNOS、iNOS表达明显减少 (P <0 .0 1) ,氨氯地平组eNOS表达上调 (P <0 .0 1) ,iNOS下调 ;再灌注 2 0min时 ,高胆固醇血症组冠脉血管内皮表达iNOS增多 ,氨氯地平组eNOS、iNOS表达明显下调 ;再灌注 2h时 ,氨氯地平组NO水平及eNOS、iNOS表达较高胆固醇血症组轻度降低。各时相点L NAME均可部分阻断氨氯地平对eNOS、iNOS的效应。结论 :在高胆固醇血症时、缺血期及再灌注早期 ,氨氯地平可调节eNOS、iNOS表达 ,减少心肌缺血 再灌注损伤。     

17β-雌二醇后处理对离体大鼠心肌缺血再灌注损伤的研究

目的：探讨17β-雌二醇（17β-estradiol,E2）后处理对缺血再灌注损伤离体大鼠心肌的影响。方法：采用Langendorff装置建立大鼠离体心脏缺血再灌注模型,随机分3组,其中后处理组（Pos组）在复灌时给予3次30s短暂开放／30s阻断,雌激素组（E2组）灌注液中含有17B-雌二醇。定时收集冠脉流出液测定冠脉流量（CF）;检测缺血前及复灌后冠脉流出液中LDH、SOD、CK的含量;测定缺血区心肌梗死面积,电镜下观察心肌超微结构变化。结果：复灌后各时点CF值在Pos,E2组较Isc组恢复好（P〈0．05）,复灌30min后Pos,E2组中CK、LDH漏出量较少,SOD含量较高伙0．05）,Pos,E2组心肌梗死面积减小（P〈0．05）。结论：机械后处理、17β-雌二醇后处理,对离体大鼠心肌有保护作用．雌激素抗氧化功能是后处理的重要机制之一。     

诱导型一氧化氮合酶在坐骨神经缺血再灌注损伤中的作用

目的 探讨坐骨神经缺血再灌注损伤的可能机制。方法 72只S—D大鼠随机分为对照组和实验组，分别于坐骨神经缺血5小时、再灌注前15分钟给大鼠腹腔内注射生理盐水或诱导型一氧化氮合菌(iNOS)抑制剂氨基服(AG)，于再灌注后0小时、6小时、12小时、24小时、72小时、7天，活体采血，取坐骨神经，并用比色法测定血一氧化氮(NO)和丙二醛(MDA)及坐骨神经iNOS的活性交化。结果 实验组6小时、12小时、24小时、72小时的NO、MDA和iNOS值均低于对照组(P＜0.05，0.01)，NO和iNOS两者呈正相关r＝0.942，P＜0．001。结论 本实验证明人鼠坐骨神经再灌注损伤要比单纯缺血引起的损伤更为严重，iNOS抑制剂AG可抑制血由iNOS诱生表达所形成的NO在坐骨神经缺血再灌注损伤中的毒性作用，可减轻周围神经损害。     

川芎嗪对大鼠肾缺血-再灌注后核因子-kB表达与一氧化氮合酶活性的影响

目的 研究川芎嗪对肾脏缺血-再灌注后肾功能、核因子-κB(NFκB)的表达及一氧化氮合酶(NOS)活性的影响.方法 将30只SD大鼠随机分为假手术组、缺血-再灌注模型组和川芎嗪处理组,化学法检测血清肌酐(Cr)和尿素氮(BUN)浓度以及左肾组织中一氧化氮合酶活性,HE染色后镜下观察肾脏病理变化,免疫组化测定肾组织NF-KB的表达水平.结果 川芎嗪15,30,45 mg·kg-1剂量于缺血前静脉注射均能降低再灌注时肾脏组织中NF-κB的表达.抑制诱生型NOS(iNOS)活性、降低尿素氮和肌酐水平,其中以15 mg·kg-1作用最为显著.结论 川芎嗪15,30,45mg·kg-1剂量均能减轻肾缺血损伤,其机制可能与抑制NF-κB的表达、降低iNOS活性有关,且该作用与川芎嗪的剂量相关,以15 mg·kg-1剂量的效果最好.     

雷诺嗪后处理对大鼠离体心肌缺血/再灌注损伤的保护作用

雷诺嗪被认为是新型调节心肌代谢药物,在不影响细胞功能的前提下,降低细胞对氧的需求,改善氧的代谢,缓解心肌缺氧,从而缓解心绞痛[1].雷诺嗪预处理的心肌保护作用已有研究[2],雷诺嗪后处理是否亦具有心肌保护作用尚未见报道.本研究将利用大鼠离体心脏缺血/再灌注损伤模型,观察雷诺嗪后处理的心肌保护效应,并与雷诺嗪预处理比较.     

舒芬太尼后处理对大鼠心肌缺血再灌注中IL-6、IL-10的影响

目的 通过观察舒芬太尼后处理对大鼠心肌缺血再灌注中IL-6、IL-10的影响,探讨舒芬太尼后处理对心肌的保护作用.方法 40只Wistar大鼠随即分为假手术组(A组):只穿线,不结扎;缺血再灌注组(B组):缺血30 min后,再灌注120 min;缺血后处理组(C组):缺血30 min末行缺血30 s,再灌注30 s,重复3次,再灌注120 min;舒芬太尼后处理组(D组):缺血30 min再灌注前5 min静脉滴注舒芬太尼0.1 μg/kg,再灌注120 min.结扎大鼠心脏冠状动脉左前降支制备心肌缺血再灌注损伤模型,用ELISA方法 观察各组在各采血时间点血清中IL-6、IL-10的含量,并计算心肌梗死面积.结果 与假手术组相比,缺血再灌注组IL-6、IL-10含量均增高;与缺血再灌注组相比,缺血后处理组IL-6含量降低,IL-10含量增高;与缺血后处理组相比,舒芬太尼后处理组IL-6含量降低,IL-10含量增高,且4组含量数据差异均有统计学意义(P < 0.05).结论 舒芬太尼后处理对大鼠心肌缺血再灌注具有保护作用,舒芬太尼后处理可能通过调控对大鼠心肌缺血再灌注血清中的IL-6、IL-10含量来发挥对心肌细胞的保护作用.     

藏药莪达夏对大鼠心肌缺血再灌注NO和NOS的影响

目的 本实验主要探讨藏药莪达夏水提物对大鼠心肌缺血再灌注后,心肌组织中一氧化氮(NO)含量、一氧化氮合酶(NOS)、诱导性一氧化氮合酶(iNOS)活性的影响,从而探讨其对心肌缺血-再灌注损伤保护作用可能的保护机制。方法 采用结扎大鼠冠脉左前降支方法造成心肌缺血再灌注模型,测定再灌注40min后心肌组织中NO含量以及NOS、iNOS的活性。结果 心肌组织中NOS、iNOS活性和NO含量水平,缺血再-灌注模型组明显高于正常对照组。莪达夏水提物高、中、低剂量组心肌组织中NOS、iNOS活性水平以及NO含量水平均低于模型组。结论 藏药莪达夏能够通过降低NOS、iNOS活性和NO含量水平从而对大鼠缺血-再灌注心肌损伤产生保护作用。     

缺血后处理对大鼠缺血再灌注心肌的保护作用

目的观察缺血后处理对大鼠缺血再灌注心肌的保护作用,进一步探讨其心肌保护的作用机制。方法雄性Wistar大鼠随机分为3组:假手术组,缺血再灌注组,缺血后处理组,每组8只。建立在体心肌缺血再灌注模型,监测左室收缩压、左室舒张末压等心功能指标的变化;测定丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力。结果与假手术组比较,缺血再灌注组和缺血后处理组的心功能水平均显著降低,MDA含量显著增高,SOD活力显著下降(P<0.01);但与缺血再灌注组比较,缺血后处理组心功能恢复水平增高,SOD活力上升(P<0.05),MDA含量显著降低(P<0.01)。结论缺血后处理具有明确的心肌保护功能,可以改善心功能,减轻氧化应激损伤。     

不同浓度的L-精氨酸在心肌缺血再灌注损伤中的不同效应

目的 观察L-精氨酸-一氧化氮途径（L-Arg-NO)是否对心肌再灌注损伤有影响，以及不同浓度的L-精氨酸（L-Arg)的不同效应，方法 将48只雄性SD大鼠随机分为6组。缺血对照组，1mM组，3mM组，10mM组，30mM组，100mM组，进行离体心脏灌流实验观察缺血前及再灌注后左心功能，冠脉流出液中乳酸脱氢酶，心肌TP含量，结果 1mM组，3mM组再灌注后心功能指标，心肌酶溢出量，心肌组织ATP含量，以及心肌细胞超微结构均较对照组为佳。10mM组，30mM组再灌注后心功能恢复率，心肌组织ATP含量，电镜超微结构与对照组相比无明显差异。100mM组再灌注后心肌酶溢出量较对照组明显增高。结论 （1）在缺血前予1mM,3mM的L-Arg能减轻再灌注损伤；（2）而给予高于3mM的L-Arg并不能减轻再灌注损伤，100mM组甚至加重了再灌注损伤，说明L-Arg在缺血再灌注损伤中发挥双重作用。     

Upregulation of muscarinic receptors by long-term nitric oxide inhibition in the rat ileum

1. The aim of the present study was to examine the effects of long-term nitric oxide (NO) blockade on contractions of the rat ileum induced by muscarinic agonists. 2. Male Wistar rats received the NO synthesis inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 20 mg/rat per day) in drinking water for 7, 15, 30 and 60 days. Concentration-responses curves to methacholine and carbachol were obtained and pEC50 values were calculated. Saturation binding assays were performed in membranes prepared from rat ileum after 60 days of l-NAME treatment and the dissociation constant (KD) and maximal number of binding sites (Bmax) were determined by Scatchard analysis. 3. The NO synthase activity of the ileum was markedly reduced in all l-NAME-treated groups. At 60 days after l-NAME treatment, a significant increase in the potency of methacholine (fourfold) and carbachol (threefold) was observed. In binding studies, we found a significant increase in Bmax for [3H]-quinuclidinyl benzilate of approximately 57% in the l-NAME treated group without any significant change in KD values. The contractile response to methacholine was not modified by the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (3 micro mol/L). No morphological alterations in the rat ileum were observed in l-NAME-treated rats. 4. Our findings suggest that treatment with l-NAME for 60 days induces a marked increase in the potency of methacholine and carbachol, as well as an increase in receptor number in the rat ileum.     

Effects of chronic inhibition of nitric oxide synthase in the genetically hypertensive rat

1. The effects of graded inhibition of nitric oxide synthase (NOS) on blood pressure in the genetically hypertensive (GH) rat strain and NOS activity in regions of the brain (cerebellum, striatum, hippocampus, frontal cortex and medulla oblongata) as a measure of body NOS inhibition were studied. 2. Male GH and normotensive (N) rats (n = 7-10 per group) were given N(G)-nitro-L-arginine methyl ester (L-NAME; 2, 5, 10 or 20 mg/kg per day in drinking water) from age 7 weeks. Age- and weight-matched controls received water only. Systolic blood pressure (SBP) was measured weekly by the tail-cuff method from age 6 weeks. By age 10 weeks, rats were killed and NOS activity was measured. 3. Some GH rats that received over 5 mg/kg per day L-NAME developed stroke-like symptoms and were killed before the end of the treatment period. 4. No difference in NOS activity was found between untreated N and GH strains but, in those that received treatment, a graded inhibition was observed with increasing L-NAME dose levels. The frontal cortex in the GH strain given 20 mg/kg per day L-NAME had NOS inhibition of 90% where the N strain had 73% inhibition. Similar results were seen in the other areas of the brain. 5. Left ventricular mass, weight related, was significantly greater in the GH compared with N and was further elevated by treatment with L-NAME. 6. The SBP at 10 weeks was significantly elevated in GH rats by NOS inhibition with L-NAME in a dose-dependent manner; 25% for 2 mg/kg per day, 31% for 20 mg/kg per day (P < 0.001). There was a non-significant increase in BP in the N-treated groups (average change of 7.5%). 7. Nitric oxide synthase inhibition causing increased SBP in GH rats suggests an abnormality in the nitric oxide-L-arginine pathway in this strain.     

一氧化氮合酶抑制剂氨基胍对脑缺血大鼠脑组织氨基酸含量的影响(英文)

目的　探讨氨基胍对大鼠脑缺血组织的保护作用及其作用机制。方法　采用线栓法复制大鼠中脑动脉梗死模型,缺血后给予氨基胍治疗。相应时间断头取脑,然后测定脑梗死体积、脑组织中氨基酸的含量。结果　脑梗死体积氨基胍组较缺血组明显缩小;缺血组比假手术组纹状体、海马、皮质中天门冬氨酸、谷氨酸、甘氨酸、GABA含量显著增加,给予氨基胍治疗后,天门冬氨酸、谷氨酸的含量明显降低,甘氨酸、GABA含量明显升高。结论　氨基胍降低脑组织中兴奋性氨基酸的含量,升高抑制性氨基酸的含量可能是保护脑缺血的重要机制     

香菇多糖对巨噬细胞一氧化氮和一氧化氮合酶活性的影响

目的研究香菇多糖(LTN)诱导巨噬细胞的一氧化氮(NO)生成和一氧化氮合酶(iNOS)的活性,探讨LTN的免疫调节作用机理.方法采用Griess反应和荧光法测定不同剂量的LTN作用小鼠腹腔巨噬细胞后NO的生成量和iNOS活性.观察mRNA转录抑制剂、蛋白质合成抑制剂和iNOS抑制剂对巨噬细胞NO的生成和iNOS活性的影响.结果LTN能使小鼠腹腔巨噬细胞NO生成增加,iNOS活性增高,并呈作用剂量依赖关系.3种抑制剂均能抑制LTN诱导的小鼠腹腔巨噬细胞N0的生成和iNOS活性.结论LTN能刺激小鼠腹腔巨噬细胞提高iNOS活性和NO的生成.提示LTN的免疫调节作用机制可能与LTN刺激巨噬细胞NO生成有关.     

吡那地尔缺血后处理对大鼠心脏的保护作用

目的研究吡那地尔缺血后处理对离体大鼠心脏缺血/再灌注损伤的影响。方法应用Langendorff离体心脏灌流技术建立大鼠全心缺血/再灌注模型和膜片钳细胞贴附式记录技术。结果①与对照组比较,缺氧/复灌组表现出明显的心脏损伤效应,复灌过程中各项心功能指标(LVDP、±LVdp/dtmax)的恢复均低于对照组(P<0.05);与缺氧/复灌组比较,经吡那地尔缺血后处理组的顿抑心肌收缩功能恢复明显提前(P<0.01),心功能(LVDP、±LVdp/dtmax)恢复增强(P<0.05);②吡那地尔在缺血/再灌注条件下提高KATP通道的电流幅度,增加通道的开放概率,各组之间比较差异有显著性(P<0.01)。结论短暂低氧方式同时经吡那地尔缺血后处理,可增强大鼠顿抑心脏对缺血/再灌注损伤的抵抗能力,表现出明显的心脏保护作用。     

一氧化氮对大鼠肝脏缺血再灌注细胞凋亡的影响

目的:探讨一氧化氮在大鼠肝脏缺血—再灌注细胞凋亡中的作用机制。方法:采用动物分组对照实验,研究了L—精氨酸(NO供体)对大鼠肝缺血再灌注细胞凋亡的影响,测量不同状态下动物肝脏组织中NO- 3/NO- 2 含量和细胞凋亡百分率(AI)的变化。结果:肝组织中一氧化氮代谢产物NO- 3/NO- 2 含量明显增加,并且肝组织中细胞凋亡百分率(AI)明显减小。结论:一氧化氮对肝脏缺血再灌注细胞凋亡有抑制作用,本实验为一氧化氮在肝缺血再灌注损伤的临床治疗提供实验基础。     

雪莲提取物对脑缺血再灌注损伤小鼠皮层区一氧化氮合酶亚型表达的影响

目的 探讨雪莲提取物对脑缺血再灌注损伤后小鼠皮层3种一氧化氮合酶(NOS)亚型表达的影响.方法 32只健康雄性ICR小鼠完全随机分为假手术组、生理盐水组、雪莲注射液组和依达拉奉组,每组8只,分别给予生理盐水、雪莲注射液或依达拉奉7d后,制作大脑中动脉阻塞模型,缺血60 min再灌注24h后应用免疫组化染色观察计算缺血皮层区每个高倍镜视野下3种NOS亚型的表达.结果 脑缺血再灌注损伤后24h,生理盐水组小鼠皮层神经元型一氧化氮合酶(nNOS)、诱导型一氧化氮合酶(iNOS)及内皮型一氧化氮合酶(eNOS)表达分别为(14.0±4.8)个/HP、(15.0±5.5)个/HP、(18.2±5.5)个/HP,较假手术组[(2.1±0.8)个/HP,(1.3±0.6)个/HP,(3.3±1.9)个/HP]均明显上调(P均为0.000).雪莲注射液组模型制作后皮层nNOS及iNOS阳性细胞表达分别为(7.5±3.8)个/HP、(7.1±3.7)个/HP,较生理盐水组明显减少(P均为0.000);eNOS阳性细胞表达为(22.3±2.3)个/HP,与生理盐水组比较差异无统计学意义(P=0.072).结论 雪莲提取物通过抑制脑缺血再灌注损伤后nNOS及iNOS表达,从而发挥神经保护作用.     

Prevention and/or treatment of ischemic stroke with nitric oxide synthase substrates

Previous studies have shown that nitric oxide (NO) synthase substrates such as L-arginine and N_α-benzoyl-L-arginine ethyl ester (BAEE) are capable of lowering intraocular pressure and improving ocular blood flow. Therefore, it is hoped that these agents could improve the cerebral blood flow after ischemic stroke and to prevent or reduce cerebral neuronal damages. Rat ischemic stroke was induced by an occlusion of middle cerebral artery and common carotid artery for 60 min. The occlusion was then released and the extent of neural damage was measured by the measurement of necrosis areas. L-Arginine and BAEE were able to prevent neural damages by 99% and 94% respectively, at 1 h; 96% and 86%, respectively, at 6 h; and 90% and 77%, respectively, at 24 h after ischemia. A marked concentration-response increase of c-AMP was observed by both L-arginine and BAEE in the cultured aortic A7r5 cells. These results indicate that NO synthase substrates are able to prevent/reduce ischemic stroke possibly through improvement of cerebral blood flow and via conservation of high energy phosphate compounds such as c-AMP. Drug Dev. Res. 40:88–93, 1997. © 1997 Wiley-Liss, Inc.     

Selective peripheral regulation of noradrenaline and adrenaline release by nitric oxide

1. Nitric oxide (NO) has complex effects on the sympathoadrenal and cardiovascular systems and may act at both central and peripheral loci. Nitric oxide appears to act directly on blood vessels and indirectly by modulating the sympathoadrenal system. In the present study, we investigated the contribution of catecholamine release from peripheral vascular and adrenal sympathetic nerves to the cardiovascular effects of the NO synthesis inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 10 mg/kg). Our experiments were performed in pithed vagotomized rats to remove the influence of central and baroreflex pathways. 2. Spinal cord stimulations for 30 s periods at 1, 2, 5 and 10 Hz using pulses of 1 msec at 10 V caused marked increases in plasma adrenaline and noradrenaline. N(G)-Nitro-L-arginine methyl ester did not alter resting plasma catecholamine concentrations. However, L-NAME generally more than doubled stimulation-evoked release of adrenaline while reducing the extent of noradrenaline release relative to vehicle (saline)-treated controls. 3. N(G)-Nitro-L-arginine methyl ester significantly enhanced the vasopressor responses to spinal cord stimulation. The alpha1-adrenoceptor antagonist prazosin (0.2 mg/kg) reduced the pressor responses of electrically stimulated L-NAME-treated rats to levels below those of vehicle-treated control rats. 4. In the absence of electrical stimulation, L-NAME raised the blood pressure of pithed rats without altering plasma catecholamines and the pressor effect was briefly attenuated by L-arginine, but was unaffected by prazosin. 5. We conclude that the augmented pressor response to sympathetic stimulation in L-NAME-treated pithed rats is due largely to enhanced adrenal adrenaline release mediated by a peripheral mechanism. Stimulation of alpha(1)-adrenoceptors plays a major role in the pressor response to electrical stimulation of L-NAME-treated rats, but this is not due to L-NAME augmentation of noradrenaline release from vascular sympathetic nerves.     

一氧化氮合酶抑制剂的研究进展

一氧化氮（ｎｉｔｒｉｃｏｘｉｄｅ,ＮＯ）是一种能调节细胞多种功能的信息分子,它参与心血管、外周和中枢神经以及免疫等系统生理过程和生物信号的调节。体内组织中的ＮＯ由ＮＯ合酶（Ｎｉｔｒｉｃｏｘｉｄｅｓｙｎｔｈａｓｅ,ＮＯＳ）催化左旋精氨酸而合成,合成后的ＮＯ迅速跨膜扩散释放。各种调节ＮＯ释放的因素均作用于ＮＯＳ催化的化学反应过程,而体内影响该反应的ＮＯＳ在各组织的表达不同。特异性ＮＯＳ抑制剂通过调控ＮＯ的合成,对ＮＯＳ表达相关的各种疾病的预防和治疗具有重要的临床意义。本文对近年来ＮＯＳ抑制剂的研究进展作一概述。