一氧化氮合酶抑制剂对创伤性休克的干预作用

目的：评价选择性诱导型一氧化氮合酶（iNO）抑制剂氨基胍（AG）和非选择性一氧化氮合酶抑制剂L-N位硝基精氨甲酯（L-NAME）对创伤性休克的治疗效果。方法：40只Wistar大鼠制作创伤性休克动物模型。双侧股骨干砸伤后并经股动脉放血至平均动脉压（MAP）35～45mmHg（4．67～6.00kPa），维持30min，然后回输失血和等量的林格式液。随机分为休克组（10只）,AG组（根据复苏时静脉注射AG含量为10，50mm／kg。则分为AGⅠ，AGⅡ各10只），L-NAME组（10只，复苏时静脉注射LNAME10mg/kg），观察休克前后血浆NO浓度的动态变化及24h大鼠存活率。并留取肺、肝、肾、小肠组织，观察病理改变。结果：大鼠创伤性休克后，血浆NO水平明显高于休克前；AG各组动物复苏后血浆NO的水平明显降低，各脏器的病理损害亦显著减轻，存活率明显提高，AGⅡ组效果最好；L-NAME组动物复苏后血浆NO的水平也明显降低，各脏器的病理损害无明显变化，存活率无明显提高。结论：NO在创伤性休克的病理发展过程中起着重要作用，应用AG有助于创伤性休克的改善；L-NAME能降低NO的水平，但对休克的预后无明显改善。     

选择性、非选择性内皮素受体拮抗剂对创伤性休克大鼠的影响

目的 探讨选择性、非选择性内皮素(ET)受体拮抗剂对创伤性休克大鼠的影响。方法 采用后肢创伤法建立创伤性休克大鼠模型,随机分为休克组、休克+BQ-123组和休克+PD142893组,分别于创伤前、休克末、复苏后 1、3、5 h检测血浆内皮素及骨骼肌、肝脏、小肠的组织氧分压,监测血流动力学变化并记录存活时间。结果 3组大鼠休克末及复苏后备时间点血浆内皮素浓度及组织氧分压较伤前差异有显著性(P<0.05),休克+BQ-123组于复苏后 1、3 h血浆内皮素浓度显著低于休克组(P<0.05),复苏后肝脏、小肠的组织氧分压较休克组显著升高(P<0.05),其 12、24 h存活率同休克组比较差异均有显著性(P<0.05)。结论 创伤性休克后血浆内皮素浓度显著升高,选择性ETA受体拮抗剂BQ-123可显著改善创伤性休克大鼠内脏组织氧分压,延长存活时间。     

氨基胍在重度失血性休克中的应用研究

目的：研究氨基胍（AG）在重度失血性休克中的治疗效果。方法：采用兔失血性休克－复苏模型,分为休克组,AG组（复苏时应用AG）,观察休克前后血浆内毒素（ET）,肿瘤坏死因子（TNF）－α,白细胞介素（IL）－6,IL－8,一氧化氮（NO）的变化,观察动物24,48h存活率。结果：兔失血性休克后,血浆内毒素,TNF－α,IL－6,IL－8,NO水平明显升高;复苏后,AG组动物血浆中上述物质水平明显低于休克组,该组动物的存活率明显高于休克组。结论：内毒素血症,TNF－α,IL-6,IL-8,NO在失血性休克的发展过程中起着重要作用,AG作为诱导型一氧化氮合酶（iNOS)抑制剂,有助于改善重度失血性休克的预后。     

诱导性一氧化氮合酶抑制药对感染性休克鼠肝、肺组织学改变的影响

目的　研究诱导性一氧化氮合酶 ( i NOS)抑制药氨基胍 ( AG)和非选择性 NOS抑制药L- N-硝基精氨甲酯 ( L- NAME)对感染性休克鼠肝肺组织学改变的影响。方法　小鼠腹腔内注射 ( i.p.)内毒素 ( L PS,2 0 mg· kg- 1 )后 4小时随机分为 L PS组 ( n=60 ) ,L PS L - NAME组 ( 3 0 mg· kg- 1i.p.,n=60 )。和 L PS AG组 ( 2 0 mg· kg- 1 i.p.,n=60 )。5小时后取受试鼠的肝肺组织进行光镜和电镜检查。并观察 2 4小时内受试鼠的生存率。结果　 L PS组、L PS L- NAME组和 L PS AG组 2 4小时内生存率分别为 3 7.5 % ,5 %和 64 .3 % ( P<0 .0 5 )。光镜下 L PS组和 L PS L- NAME组肝细胞和核肿胀 ;肺间质增厚。电镜下可见 L PS组和 L PS L- NAME组可见肝细胞核、细胞膜和线粒体膜明显破坏 ;肺血气屏障明显增厚。 L PS AG组肝细胞和肺部的改变明显轻于其它两组。结论　感染性休克中 c NOS介导的一定量的 NO对器官有保护作用。以氨基胍选择性抑制 i NOS合成的 NO,疗效好于非选择性 NOS抑制药     

一氧化氮对急性水肿型与坏死型胰腺炎发病机理的不同作用

微循环改变和白细胞-内皮的相互作用是急性胰腺炎的二个主要的病理改变。作者通过实验鼠的轻型（水肿型）和重型（坏死型）胰腺炎模型，研究了一氧化氮（NO）供体（静脉内输入或吸入）和NO抑制剂对这二种病理过程的影响。各100只轻型、重型胰腺炎鼠模型。每组随机分成五个相等数的治疗亚组：对照组，NO-合酶基质L-精氨酸，NO供体硝普钠（SNP），NO-合酶（NOS）抑制剂N-硝基-L-精氨酸甲基酯（L－NAME）和NO吸入。6小时后用湿／干重量比率测定水肿。通过测组织中胰蛋白酶原活性多胜（TAPs）的水平和组织学分析炎症和坏死来确定胰…     

一氧化氮合酶抑制剂对鼠急性坏死性胰腺炎的作用

一氧化氮（NO）由一氧化氮合酶（NOS）生成,已知NO与炎症过程密切相关,为了阐明原生型NOS抑制剂（NG－硝基－L－精氨酸甲基酯,L－NAME）和诱生型NOS抑制剂（氨基－乙基－异硫脲,AE－ITU）对鼠急性坏死性胰腺炎的作用,作者进行实验研究如下：取SD鼠作为实验对象,在麻醉下用蛙皮素等制成急性坏死性胰腺炎模型,共分6组,每组鼠15只：（1）盐水对照组,不制成胰腺炎模型,仅持续输往盐水每小时8ml／kg,共12小时;（2）L－NAME对照组,其手术步骤同第1组,但在第6、7和8小时各注射L－NAME30mg／kg一次;（3）AE－ITU对…     

L-精氨酸在犬离体胰腺低温灌注与保存中的作用

目的　探讨L -精氨酸对犬离体胰腺低温灌注及保存中缺血再灌注损伤的影响。方法　将犬胰节段移植模型动物随机分为 3组 :(1)L -精氨酸灌注保存组 (L -arg组 ) ,在EuroCollin(EC )液中加用L -精氨酸 ;(2 )硝基精氨酸组 ,在EC液中加入N -硝基 -L -精氨酸甲酯 (L NAME) ;(3 )对照组 ,在EC液中加入生理盐水 ;分别对犬离体胰腺节段进行低温灌注保存。测定移植后犬血清中脂肪酶和淀粉酶含量 ,并测定移植胰腺组织中髓过氧化酶 (MPO )活性、一氧化氮 (NO )含量、一氧化氮合酶 (NOS)及iNOSmRNA的表达 ;同时进行组织学观察。结果　血清脂肪酶含量 :L arg组 <对照组 对照组 >L NAME组。NOS活性 :L arg组 >对照组 >L NAME组。iNOSmRNA的表达 :L arg组 >对照组 >L NAME组。MPO活性 :L arg组 <对照组 相似文献   

阻塞性黄疸时L-精氨酸对肾功能的保护作用

目的：研究阻塞性黄疸（OJ）时，L－精氨酸（L－Arg)对肾功能的保护作用。方法：胆总管结扎大鼠30只，随机分成生理盐水对照（NS）组、L－精氨酸（L－Arg)组和L－硝基精氨酸（L－NNA）组，每组10只。胆总管结扎后第2天起分别腹腔注射1ml NS、1ml L-Arg(500mg/kg)、1ml L-NNA(10mg/kg)，连用9d；假手术（SO）组用1ml NS腹腔注射。观察各组肾功能的变化，同时测定血和肾组织内皮素（ET）、一氧化氮（NO）水平、一氧化氮合酶（NOS）活性和丙二醛（MDA）的含量。并用图像分析检测ET1 mRNA和NOS mRNA表达的部位及量的变化。结果：用L－Arg后，血和肾组织NOS活性增加，肾组织ET1 mRNA表达减少，血和肾组织ET下降，NO升高；同时伴有内生肌酐清除率（Ccr)、肾皮质平均血流（RCBF）的升高，肾组织MDA含量降低。结论：L－Arg通过增强血和肾组织NOS活性来增加体内NO水平、抑制ET1 mRNA表达、降低体内ET水平，从而提高Ccr与RCBF，减轻阻塞性黄疸时的肾功能损伤。     

一氧化氮对大鼠移植胰腺再灌注损伤的保护作用

目的　探讨一氧化氮 (NO)对大鼠移植胰腺再灌注损伤的保护作用。方法　应用同系大鼠异位全胰十二指肠移植模型 ,大鼠移植术前和术后 5min静脉注射L 精氨酸 (L Arg ,2 0 0mg/kg)和N 硝基 L 精氨酸甲酯 (L NAME ,10mg/kg) ,移植术后 1～ 72h经腹主动脉取血测定大鼠空腹血糖、血清中脂肪酶、淀粉酶及中性粒细胞化学趋化性细胞因子 (CINC)含量 ,测定移植胰腺组织中NO含量、CINCmRNA的表达及髓过氧化酶 (MPO)活性 ,并进行组织学观察。结果　移植胰腺组织中NO含量L Arg组 >对照组 >L NAME组 ;CINC在再灌注后 3h出现峰值 ,L Arg组为(7.66± 1.5 3 ) μg/L ,L NAME组为 (3 4.18± 3 .12 ) μg/L ,对照组为 (2 6.3 1± 2 .0 1) μg/L ,差异有显著性 (P <0 .0 5 ) ;移植物中CINCmRNA于再灌注后 3h表达最强 ,L Arg组表达水平明显低于L NAME组和对照组 ;L Arg组胰小叶间质水肿和胰小叶内中性粒细胞浸润较轻。 结论　外源性应用L Arg或L NAME能够分别增加或减少胰腺组织NO含量 ,NO能抑制CINC的升高及CINCmRNA的表达 ,抑制中性粒细胞浸润 ,对移植胰腺再灌注损伤起保护作用。     

大鼠肝缺血／再灌注后肝组织一氧化氮和不同亚型一氧化氮合酶的变化

目的探讨一氧化氮（NO）和一氧化氮合成酶（NOS）在肝缺血／再灌注（I／R）过程中的变化和作用。方法健康雄性SD大鼠24只，随机分为3组（每组8只）：①正常对照组，术中只分离肝周围韧带，不做肝门阻断及再灌注。②I/R组，进行45min的部分肝门阻断及60min的再灌注。③L-精氨酸（L—Arg）组，缺血前20min经阴茎背静脉注射L—Arg（300mg／kg），余同②组。实验结束后，取下腔静脉血2ml，并迅速切取缺血肝组织。检测血清丙氨酸转氨酶（ALT）、门冬氨酸转氨酶（AST）、乳酸脱氢酶（LDH）；测定肝组织中超氧化物歧化酶（SOD）、丙二醛（MDA）、黄嘌呤氧化酶（XOD）、一氧化氮（NO）和一氧化氯合成酶（NOS）等指标；观察光镜和电镜下肝组织学变化。结果与正常对照组相比，I／R组iNOS升高，NO降低；L-Arg组NO、eNOS均高于I／R组。2、3组比1组大鼠的肝组织病理损害重、肝功能差，L—Arg组病理损害较I／R组明显减轻、肝功能改善。结论NO对大鼠肝I／R损伤具有保护作用．不同亚型NOS的变化参与其中。     

内皮素拮抗剂对创伤性休克大鼠的影响

目的　研究内皮素在创伤性休克过程中的意义 ,探讨咖啡酸拮抗内皮素对创伤性休克治疗的影响。方法　建立创伤性休克动物模型 ,根据应用咖啡酸的不同分为A组 (不用药 )、B组(创伤前用药 )、C组 (复苏即刻用药 )及D组 (复苏 3h用药 ) ,检测复苏后 5h血浆内皮素及组织氧分压 ,监测血液动力学变化并记录存活时间。结果　应用咖啡酸各组于复苏 5h血浆内皮素浓度均较A组低差异有显著性 (P <0 .0 5 ) ,复苏 5hB组的组织氧分压及平均存活时间较A组明显降低且有显著性 ,而D组同A组相比可明显改善组织氧分压 ,延长平均存活时间。结论　内皮素在休克早期对于维持血压有重要意义 ,早期应用咖啡酸拮抗内皮素反而使模型平均存活时间下降 ,而于休克后期应用咖啡酸拮抗内皮素可明显改善组织氧分压 ,延长模型存活时间。     

The role of selective nitric oxide synthase inhibitor on nitric oxide and PGE2 levels in refractory hemorrhagic-shocked rats

BACKGROUND: The up-regulation of nitric oxide (NO) and cyclooxgenase-2 (COX-2) has been implicated in the pathophysiology of hemorrhagic shock. We examined the effects of aminoguanidine (AG), which is a known inducible nitric oxide synthase (iNOS) inhibitor, and NS-398, a known COX-2 inhibitor, in our rat model of refractory hemorrhagic shock (RHS). MATERIAL AND METHODS: We measured tissue iNOS and COX-2 protein expression, brain and plasma nitrate/nitrite and prostaglandin E2 (PGE2) levels, plasma creatinine and glutamic oxalacetic transaminase (GOT) levels, quantified the histological damages in kidney, liver, lung, and brain, survival rate, and mean arterial blood pressure (MABP) in RHS rats. RESULTS: Semiquantitative analysis of tissues showed iNOS protein was not detected in AG + RHS rats but was detected in normal saline and NS-398 RHS rats. Tissue COX-2 protein was not detected in AG and NS-398 RHS rats but was detected in normal saline + RHS rats. The levels of brain and plasma nitrate/nitrite and PGE2 and plasma creatinine and GOT were significantly lower in the AG + RHS rat group when compared with the normal saline RHS rat group. Histological examinations also showed a reduction in organ damage for AG + RHS rats when compared with treated RHS rats. AG + RHS rats showed significantly increased survival and MABP level when compared with treated RHS rats. CONCLUSION: Our present findings suggest that NO produced by iNOS might result in organ damages. This in turn might lead to COX-2 up-regulation, and it increases the production of reactive oxygen species and toxic prostanoids. NO-mediated organ damage might be one way in which toxic products of COX-2 might further contribute to NO's deleterious effect in the later stages of RHS. It is therefore suggested that treatment of AG via inhibition of NO might contribute to improved physiological parameters and survival rates following RHS.     

Effective inhibition of nitric oxide production by aminoguanidine does not reverse hypotension in endotoxaemic rats

BACKGROUND: Excess production of nitric oxide (NO) by the inducible NO synthase (iNOS) has been implicated in the pathophysiology of septic shock. Using methaemoglobin (metHb) and the stable NO metabolite nitrate as markers of NO formation, we assessed the effect of iNOS blockade by aminoguanidine (AG) on hypotension and NO formation in endotoxaemic rats. METHODS: In 32 male Wistar rats under chloralose anaesthesia, MetHb (at 15 and 330 min, respectively) and plasma nitrate (at 330 min) were determined. Mean arterial pressure, heart rate and haematocrit were monitored. The LPS group (n=8) received bacterial endotoxin (LPS), 3 mg kg(-1) i.v. and was subsequently monitored for 5 h. At 2 h after LPS, the LPS+AG20 group (n=8) received AG, 5 mg kg(-1), and 5 mg kg(-1) h(-1) for the remaining 3 h. The LPS+AG100 group (n=8) instead received 25 mg kg(-1), followed by 25 mg kg(-1) h(-1). The NaCl group (n=8) was given corresponding volumes of isotonic saline. RESULTS: AG decreased the LPS-induced rise in plasma nitrate by about 50% in the LPS+AG20 group. MetHb levels, however, were not appreciably reduced by this dose. Both NO metabolites reached control levels after the higher dose of AG. LPS caused a progressive decrease in haematocrit. AG did not influence the LPS-induced hypotension, tachycardia or haemodilution. CONCLUSION: AG inhibited NO formation in a dose-dependent way. Yet, AG had no haemodynamic effects, suggesting a minor cardiovascular influence of iNOS in this endotoxin model, in parallel to what has been found in microbial sepsis.     

细胞外信号调节激酶在内毒素休克大鼠生物喋呤诱生中的作用机制探讨

目的观察细胞外信号调节激酶（ERK）通路抑制剂对生物喋呤（BH4）和一氧化氮（NO）表达及核因子-kB（NF-kB）活化的影响,探讨内毒素休克时ERK信号通路与NF-kB的交汇作用及其对BH4诱生NO的调控机制。方法采用内毒素休克模型,60只大鼠随机分为正常对照组（n=8）、内毒素休克组（n=32）和ERK抑制剂PD98059拮抗组（n=20）。留取动物肝、肺、肾组织进行NF-kB活性分析以及三磷酸鸟苷环水解酶I（GTP—CHⅠ）、诱生型一氧化氮合酶（iNOS）基因表达的检测,并测定组织及血浆中BH4、NO水平。结果内毒素攻击可导致动物肝、肺、肾组织GTP-CHⅠ基因表达和BH4水平明显升高,至伤后24h仍持续于较高水平;与之相应,组织iNOS基因表达和NO水平亦明显升高;各组织NF-kB迅速活化,并于2h达峰值。采用PD98059处理后,内毒素休克动物肾组织GTP—CHⅠ mRNA表达明显受抑,肝、肺组织GTP—CHⅠmRNA表达仅呈现降低趋势;血浆及肝、肾组织中BH4水平12h显著降低;同样,各组织iNOS mRNA表达及NO水平早期亦显著降低。此外,PD98059处理组动物肝组织2～6h、肺组织2h、24h和肾组织24h时相点NF-KB活性显著降低。结论内毒素休克时抑制ERK通路,能部分下调BH4和NO表达与NF-kB的活化,表明ERK与NF-kB通路间可能存在交汇作用,共同参与了BH4诱生NO的调控作用。     

Chronic inhibition of nitric‐oxide synthase induces hypertension and erectile dysfunction in the rat that is not reversed by sildenafil

Study Type – Aetiology (case control)
Level of Evidence 3b

OBJECTIVE

To evaluate the effect of N(G)‐nitro‐l ‐arginine methyl ester (L‐NAME)‐induced hypertension (HT) on erectile function in the rat and determine if the phosphodiesterase (PDE)‐5 inhibitor, sildenafil, can reverse the effects of nitric oxide (NO) deficiency, as HT is a risk factor for erectile dysfunction (ED) and the NO synthase (NOS) inhibitor L‐NAME induces NO‐deficient HT.

MATERIALS AND METHODS

Thirty‐six adult Sprague‐Dawley male rats were divided into three groups, i.e. a control, L‐NAME‐HT (40 mg/rat/day in the drinking water for 4 weeks), and sildenafil‐treated L‐NAME‐HT (1.5 mg/rat/day sildenafil, by oral gavage concomitantly with L‐NAME). The erectile response expressed as a ratio of intracavernosal pressure (ICP)/mean arterial pressure (MAP), evaluated after electrical stimulation of the right cavernous nerve. The isometric tension of corpus cavernosum smooth muscle (CCSM) was measured in organ‐bath experiments. NOS expression was determined immunohistochemically for neuronal (n)NOS and by Western blot analysis for endothelial (e) and inducible (i) NOS protein. cGMP levels were evaluated by enzyme‐linked immunosorbent assay.

RESULTS

The erectile response was diminished in the HT group. Nitrergic and endothelium‐dependent relaxation was reduced, while the relaxation response to sodium nitroprusside and contractile response to phenylephrine were not altered in CCSM from L‐NAME‐treated rats. HT rats showed decreased expression of nNOS, whereas eNOS and iNOS protein expression was increased. Sildenafil partly restored endothelial and molecular changes in CCSM from HT rats, but did not reverse the decreased erectile response, even as cGMP levels returned to normal levels.

CONCLUSIONS

Sildenafil treatment did not correct the ED in L‐NAME‐treated HT rats. Under sustained high blood pressure, up‐regulation of PDE5 expression failed to reverse the depletion of neuronal NO and/or impaired nNOS activity. However, endothelium‐dependent relaxation was restored. Drug targeting of neuronal dysfunction might delay the onset of ED in HT.     

A Novel Organ Preservation for Small Partial Liver Transplantations in Rats: Venous Systemic Oxygen Persufflation With Nitric Oxide Gas

The prognosis for recipients of small liver grafts is poor. The aim of this study was to determine the impact of venous systemic oxygen persufflation (VSOP) with nitric oxide (NO) gas for 30% partial liver preservation and transplantation in rats. After we determined optimal NO concentration as 40 ppm in vitro with the isolated perfused rat liver model, we assessed liver injury and regeneration in vivo at 1, 3, 24 and 168 h after transplantation in the following three groups after 3 h‐cold storage (n = 20 per group): control group = static storage; VSOP group = oxygen persufflation and VSOP+NO group = oxygen with NO persufflation. The liver graft persufflation was achieved with medical gas via the suprahepatic vena cava; In comparison with control group after transplantation, VSOP+NO preservation (1) increased portal circulation, (2) reduced AST and ALT release, (3) upregulated hepatic endothelial NO synthase, (4) reduced hepatocyte and bileductule damage and (5) improved liver regeneration. These results suggest that gaseous oxygen with NO persufflation is a novel and safe preservation method for small partial liver grafts, not only alleviating graft injury but also improve liver regeneration after transplantation.     

脓毒症大鼠多器官高迁移率族蛋白B1基因表达的信号机制与意义

目的探讨Janus激酶／信号转导和转录激活因子（JAK／STAT）通路对盲肠结扎穿孔术（CLP）所致脓毒症大鼠多器官高迁移率族蛋白B1（HMGBl）基因表达的影响及其意义。方法采用CLP模型,大鼠随机分为正常对照组（10只）、假手术组（10只）、CLP组（60只）、JAK2抑制剂AG490干预组（24只）、STAT抑制剂雷帕霉素（RPM）干预组（24只）。留取肝、肺、肾、肠组织测定HMGB1mRNA表达和STAT1／3的DNA结合活性。结果CLP后,肝、肺、肾、肠组织中STATl在脓毒症早期即迅速活化,6-12h后活化达高峰。肝、肺组织中STAT3的活化特点与STAT1相似,但相对较弱;在肾、肠组织中未探测到STAT3的活化。同时,CLP组除肾组织HMGB1mRNA表达改变不明显外,肝、肺、肠组织其表达均明显增强（P＜0．05或P＜0．01）。AG490早期处理后24—48h,肝、肠组织HMGB1mRNA表达显著低于CLP组（P＜0．05或P＜0．01）;RPM干预组肝、肺、肠组织HMGB1mRNA表达均呈现不同程度地抑制,其中以肺组织下降幅度尤为明显。结论严重腹腔感染可导致机体主要脏器JAK／STAT通路迅速活化,该信号途径参与了HMGB1mRNA的表达调控过程。     

急性坏死性胰腺炎时NO变化及三七总甙的治疗作用

目的:探讨急性坏死性胰腺炎(ANP)大鼠体内一氧化氮(NO)在疾病发展过程中的变化规律,中药三七总甙对ANP的治疗作用及对NO的影响.方法:将120只SD大鼠随机分为假手术组、对照组及实验组,用5%牛磺胆酸钠制成ANP模型,实验组用三七总甙治疗,对照组不用药物治疗,分别于术后2 h、4 h、6 h、8 h、12 h、24 h测定血清及胰腺的NO含量,并比较生存率.结果:实验组和对照组术后2 h NO水平显著增高,8 h后开始降低,24 h仍高于正常水平.但实验组明显低于对照组,实验组的生存率亦明显高于对照组.1周生存率假手术组、ANP组、ANP 中药组分别为100%、0%、70%.结论:ANP时NO有显著变化,三七总甙对其有抑制作用,对ANP有显著的治疗作用.