氨基胍与环孢素A联用对大鼠心脏移植后急性排斥反应的影响

目的：探讨氨基胍与环孢素A联用对同种大鼠心脏移植后急性排斥反应的影响。方法：受体SD大鼠心脏移植后分为4组：（1）对照组：术后不作任何处理;（2）低剂量环孢素A（CsA)组;术后0－7d肌肉注射CsA2mg.kg^-1.d^-1;（3）氨基胍（AG）组：术后0－7d皮下注射AG600mg.kg^-1.d^-1;（4）低剂量CsA加AG组;术后0－7d肌肉注射CsA2mg.kg^-1.d^-1及皮下注射AG600mg.kg^-1.d^-1。术后4d测定急性排斥反应时移植心的诱生型一氧化氮合酶（iNOS)的表达及血清一氧化氮（NO）含量,并观察移植心存活时间。结果与低剂量环孢素A组相比较,低剂量环孢素A与氨基胍联用组不仅显著地抑制移植心iNOS表达与NO产生（P＜0．05）;而且显著地减轻急性排斥反应（P＜0．01）,延长了移植心存活时间（P＜0．05）。结论低剂量环孢素A与氨基胍联用,协同抑制急性排斥反应时移植心iNOS活性及NO产生;显著地延长移植物存活时间。     

氨基胍对内毒素休克大鼠肝损伤的保护作用研究

目的 探讨诱导型一氧化氮合酶(iNOS)抑制剂氨基胍对内毒素休克大鼠肝脏的组织学和超微结构的影响。方法 取雄性wistar大鼠24只．随机分为正常对照组、内毒素对照组和氨基胍治疗组．每组各8只。用大肠杆菌内毒素(LPS)复制大鼠内毒素性休克模型．氨基胍治疗组采用氨基胍治疗。观察并比较三组大鼠肝脏的组织学、超微结构及其血浆一氧化氮(NO)含量的变化。结果 光镜下可见．内毒素组肝组织有散在小脓肿灶形成．肝细胞坏死，中性白细胞浸润．而氨基胍治疗组的肝组织受损程度较轻。电镜下可见，内毒素组的肝细胞核出现融解性空斑．线粒体肿胀和线粒体嵴数量减少．而氨基胍则对肝脏的结构起到一定的保护作用。内毒素对照组血浆NO水平明显高于正常对照组．给予氨基胍治疗后血浆NO水平明显下降．但仍高于正常对照组。结论 氨基胍通过选择性抑制iNOS活性．抑制了大鼠内毒素休克时过量的NO的产生．保护了肝脏的功能．具有潜在的临床应用价值．值得更深入地研究。     

诱导性一氧化氮合酶在大鼠肝缺血再灌注损伤中的作用

目的 探讨诱导性一氧化氮合酶（iNOS）在大鼠部分肝缺血再灌注损伤中的作用.方法 选取雄性Sprague-Dawley大鼠30只,体重225～250 g,随机分成氨基胍（AG）组、脂多糖（LPS）组、对照组.每组均按相同方法建立70%的肝缺血再灌注损伤模型（缺血1 h,再灌注6 h）,取再灌注大鼠肝组织及血清样本.氨基胍（AG）组（n=10）：术前30 min尾静脉注射AG 100 mg/kg（质量浓度10 kg/L）;脂多糖（LPS）组（n=10）：术前30 min尾静脉注射LPS 10 mg/kg（质量浓度1 kg/L）;对照组（n=10）：术前30 min尾静脉注射生理盐水（10 μL/kg）.检测血清谷氨酸转氨酶（ALT）水平,实时荧光定量PCR测定肝组织iNOS mRNA的表达,Western blot测定肝组织iNOS蛋白的表达,考马斯法测定肝组织匀浆丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性,HE染色光镜下组织学观察等.结果 AG组与对照组相比,肝组织中iNOS mRNA表达量明显下降（P〈0.05）,iNOS蛋白表达量明显下降（P〈0.05）;ALT和MDA明显下降（P〈0.05）;SOD明显升高（P〈0.05）;肝细胞水肿较轻,排列相对整齐.LPS组与对照组相比,肝组织中iNOS mRNA表达量明显升高（P〈0.05）,iNOS蛋白表达量明显升高（P〈0.01）;ALT和MDA明显升高（P〈0.05）;SOD则明显降低（P〈0.05）;肝细胞水肿,排列紊乱,并且出现水样变性.结论 iNOS 升高会加重缺血再灌注损伤,这一过程可能通过改变氧化还原状态实现.     

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。     

氨基胍对大鼠胰岛保护作用的实验研究

目的 探讨在细胞因子与大鼠胰岛细胞共同培养过程中,诱导型一氧化氮合酶(iNOS)抑制剂氨基胍对胰岛细胞功能和存活的影响及其机理.方法 分离纯化大鼠胰岛,进行胰岛细胞培养.根据培养基中是否加入氨基胍或细胞因子IL-1β和TNF-α,按随机对照原则分为空白对照组(完全培养基)、细胞因子组(加IL-1β和TNF-α)、氨基胍组(加氨基胍)及氨基胍+细胞因子组(加氨基胍及细胞因子).检测指标包括: 培养液中NO水平、胰岛组织中iNOS活性、胰岛细胞存活情况(丫啶橙/溴乙锭染色)、胰岛细胞凋亡情况(TUNEL法)及胰岛功能(胰岛素释放试验).结果 与空白对照组比较,细胞因子组大鼠胰岛组织中iNOS的活性明显提高,培养液中NO的水平明显上升,同时胰岛细胞的存活率下降,大量细胞凋亡,胰岛素分泌明显减少(P＜0.01).与细胞因子组比较,氨基胍+细胞因子组的iNOS的活性[(3.17±0.51) U/ml比(38.93±4.72) U/ml]及NO水平[(50.5±10.4) μmol/L比(313.0±35.4) μmol/L]明显下降,胰岛细胞存活率活明显升高[(72.73±3.14)%比(57.07±5.07)%],凋亡率明显下降[(20.11±8.48)%比(41.17±6.87)%],胰岛素分泌指数明显升高(3.50±0.27比1.96±0.19),差异均有统计学意义(P＜0.01).结论 氨基胍通过抑制iNOS活性,控制NO过量产生,从而减轻细胞因子对胰岛的损害,改善胰岛的存活与功能.     

氨基胍对梗阻性黄疸大鼠治疗作用的实验研究

目的 探讨诱导型一氧化氮合酶(iNOS)抑制剂氨基胍(AG)对梗阻性黄疸大鼠的治疗作用及作用机制.方法 雄性Wistar大鼠40只,随机分为正常对照组、假手术组、黄疸组、氨基胍治疗组4组,每组10只.通过测定治疗前后肝功、血胆红素、内毒素、乳酸、肝组织丙二醛水平,以及通过对肝脏、小肠的形态学分析来探讨氨基胍对梗阻性黄疽大鼠的治疗作用.结果 血浆内毒素和血清乳酸、肝组织丙二醛随着胆道梗阻时间的延长逐步升高,并伴随着肝脏小肠病理形态学的改变.氨基胍治疗组各项指标显著低于对照组,并能改善肝组织及小肠病理形态.结论 氨基胍(AG)可通过减轻脂质过氧化与内毒素血症发挥保护肝脏及小肠的作用,为治疗梗阻性黄疸患者提供了一种新的思路和方法.     

氨基胍对大鼠内毒素性肺损伤的影响

目的 观察诱导型一氧化氮合酶抑制剂氨基胍(AG)对内毒素性肺损伤的影响。方法 采用静脉注射脂多糖(LPS)制备内毒素性肺损伤大鼠模型。将40只SD雄性大鼠随机分为5组：空白对照组、LPS组、AG高剂量(100mg／kg)、中剂量(50mg／kg)、低剂量(25mg／kg)治疗组，LPS组、AG高剂量、中剂量和低剂量治疗组手术后稳定1h静脉注射LPS(5mg／kg)，空白对照组给等量生理盐水，AG高剂量、中剂量和低剂量治疗组于给予LPS 3h后经腹腔给AG，空白对照组和LPS组给等量生理盐水。实验过程中监测平均动脉压(MAP)，于注射LPS后1、3和6h时取静脉血0．4Tnl测定血浆NO浓度，于注射LPS 6h后处死大鼠，迅速取出肺脏，测定肺系数、肺含水量和肺组织中丙二醛(MDA)含量、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)活性的变化；在光镜下观察肺形态结构的变化。结果 LPS可明显降低MAP，升高肺系数和肺含水量，升高血浆中NO含量，可显著升高肺组织中NOS活性、增加MDA含量、降低SOD活性，引起肺形态结构的病理变化。氨基胍可明显改善吣引起的以上肺损伤，病理变化也表明：AG使肺泡萎陷明显减轻，肺间隔变窄，毛细血管增生不明显，肺间隔炎细胞浸润减轻，且高剂量比低剂量明显。结论 静脉注射LPS(5mg/kg)可成功制备大鼠内毒素性肺损伤模型；氨基胍可减轻内毒素性肺损伤，且随剂量增大作用增强。     

氨基胍对骨关节炎软骨细胞诱导型一氧化氮合酶的影响

目的：研究氨基胍对骨关节炎软骨细胞诱导型一氧化氮合酶的影响。方法：将32只兔子随机分组,正常组不予任何处理,试验组及对照组行右后肢伸直位管型石膏固定造模,试验组腹腔内注射氨基胍硫酸盐溶液,100mg/（kg·d）,对照组每天腹腔内注射相同体积的生理盐水。分别于4周和8周处死动物,切取标本进行后续研究。结果：与对照组相比,试验组在大体形态、HE染色方面更接近于正常组、iNOS表达阳性细胞数较少（P〈0．05）。结论：氨基胍能有效减少iNOS表达,延缓OA的病情发展。     

川芎嗪联合氨胍对糖尿病大鼠肾脏一氧化氮的影响

目的：探讨川芎嗪联合氨胍对糖尿病肾脏病变的保护作用及其机制。方法：用链脲佐菌素制作糖尿病大鼠模型，分为正常对照组、糖尿病模型组、川芎嗪治疗组、氨胍治疗组和川芎嗪联合氨胍治疗组，于第12周测定各组大鼠肾组织一氧化氮合酶的活性和一氧化氮含量。结果：川芎嗪联合氨胍治疗纪、川芎嗪治疗组、氨胍治疗组大鼠肾组织NOS活性显高于模型组(P＜0．01)，NO的含量增加(P＜0．01)。川芎嗪治疗组、氨胍治疗组NOS活性低于正常对照组(P＜0．01)，NO的合量降低(P＜0．01)；川芎嗪合氨基胍治疗组与正常组相比无差异。结论：川芎嗪联合氨基胍能够增强糖尿病大鼠肾组织NOS活性，增加NO的含量，从而对糖尿病性肾病起一定治疗作用。     

参附注射液对大鼠移植胰缺血再灌注损伤的保护作用和机制

目的：探讨参附注射液对大鼠移植胰缺血再灌注损伤的保护作用及其机制。方法：正常SD大鼠为阴性对照组（NC组，n=6），糖尿病SD大鼠24只随机分为阳性对照组（PC组，n=6）、参附预处理组（SF组，n=6）、红参预处理组（HS组，n=6）和附子预处理组（FZ组，n=6）。除对照组外各组均行胰腺移植，24只SD大鼠为供体。SF、HS和FZ组在移植前1日及术前30min经静脉分别予受体注射参附注射液（10mg／kg）、红参注射液（9mg／kg）、附子注射液（1mg／kg），NC组和PC组在移植前1日及术前30min经静脉予受体注射同等容积生理盐水。检测各组再灌注前、后血糖；再灌注后2h血清中TNF-α和一氧化氮（NO）的含量、移植胰组织中超氧化物歧化酶（SOD）、髓过氧化物酶（MPO）和丙二醛（MDA）含量；用TUNEL法观察移植胰组织细胞凋亡情况，Western Blot法检测移植胰组织Bax和Bcl-2蛋白表达情况。结果：再灌注后SF组、HS组和FZ组较PC组血糖低，血清中TNF-α含量低，NO含量高：再灌注后SF组、HS组和FZ组较PC组移植胰组织中SOD活性高，MDA含量低，MPO活性低，凋亡指数低，Bcl-2表达高．Bax表达低，Bcl-2／Bax比值高。结论：参附注射液对大鼠移植胰的缺血再灌注损伤具有保护作用，机制可能是提高SOD的活性，增加内源性NO的合成，减少TNF-α分泌，减轻嗜中性粒细胞（PMNs）黏附与聚集，上调Bcl-2和下调Bax基因表达。     

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.     

Peroxynitrite may be involved in bladder damage caused by cyclophosphamide in rats

PURPOSE: It was previously shown that nitric oxide (NO) produced by inducible NO synthase (iNOS) is responsible for cyclophosphamide (CP) induced cystitis. In this study we evaluated whether peroxynitrite is also responsible for CP induced bladder damage in rats. MATERIALS AND METHODS: A total of 38 male albino Wistar rats were divided into 4 groups. Group 1 served as controls and was given 2 ml saline, while 3 groups received a single dose of CP (200 mg/kg) at the same intervals. Group 2 received CP only, group 3 received the selective iNOS inhibitor aminoguanidine (AG) (100 mg/kg) and group 4 received the peroxynitrite scavenger ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) (20 mg/kg). RESULTS: CP injection resulted in severe cystitis with continuous macroscopic hemorrhage, strong edema, inflammation and ulceration. Moreover, bladder tissue malondialdehyde levels, iNOS activation and urine nitrite-nitrate levels were dramatically increased. AG histologically protected bladder against CP damage and decreased urine nitrite-nitrate levels, bladder malondialdehyde and iNOS induction. Ebselen showed results similar to those of AG without changing the urinary nitrite-nitrate level and iNOS activity. CONCLUSIONS: These results suggest that not only nitric oxide, but also peroxynitrite may be important in the pathogenesis of CP induced cystitis.     

The relation between apoptosis of acinar cells and nitric oxide during acute rejection of pancreas transplantation in rats

Apoptosis is an important mechanism of immune-mediated graft damage. Nitric oxide (NO) generated by inducible NO synthase (iNOS) has been demonstrated to induce apoptosis. This study investigated whether apoptosis occurs during pancreas allograft rejection and examined the relationship of apoptosis of acinar cells and NO. The rats were divided into three groups: untreated isograft group, untreated allograft group and aminoguanidine (AG)-treated group. The pancreatic grafts were harvested on the post-transplantation day 3, 5 and 7 and were used to detect the histopathological rejection grade, the expression of iNOS and the apoptotic index (AI) of the graft. iNOS presented faint positive in the acinar cells of untreated isografts and did not change greatly after transplantation (P>0.05), the level of iNOS in the untreated allografts increased progressively (P<0.01) and at the same time point was significantly higher than that of untreated isograft group and AG-treated group (P<0.01). The transferase-mediated dUTP nick end labeling showed that the apoptotic cells were mainly acinar cells. A significant correlation between AI and iNOS was noted (P<0.01, r=0.611). Therefore, NO-mediated apoptosis of acinar cells plays an important role in acute rejection of pancreas transplantation, AG can mitigate the damage of pancreas allografts.     

银杏叶提取物预处理对胰腺移植受体大鼠 小肠肠黏膜屏障的影响

目的 ：探讨银杏叶提取物（EGb）对胰腺移植受体大鼠肠黏膜屏障的保护作用及其机制。方法 ：12只正常SD大鼠为对照组;糖尿病大鼠随机分为胰腺移植组（PT组， n =12）及银杏叶提取物预处理胰腺移植组（EGb组， n =12），大鼠均接受同系胰腺移植。EGb组于移植前1d和30min予受体静脉注射EGb （1.5mL/kg）。移植术后5 d测定小肠通透性和吸收功能，检测血清TNF-α，NO，SOD和淀粉酶活性。取受体回肠黏膜组织测定小肠黏膜湿重、微绒毛厚度及宽度、MDA含量及MPO活性。同时取肠系膜静脉血、肠系膜淋巴结、肝及脾组织行细菌培养，观察细菌易位情况。结果 ：EGb组血清TNF-α含量（ P <0.01）、淀粉酶活性（ P <0.01）、MDA含量（ P <0.05）、MPO活性（ P <0.05）、小肠通透性（ P <0.01）、细菌易位率（ P <0.01）和小肠黏膜损伤程度均低于PT组;血清NO和SOD含量、小肠吸收功能均高于PT组( P <0.01)。结论 ：EGb预处理可保护胰腺移植受体大鼠小肠肠黏膜屏障，降低细菌易位率，机制可能与抗氧化、清除自由基、减少TNF-α生成、减轻嗜中性粒细胞黏附与聚集、增加内源性NO的生成有关。     

针刀干预对L3横突综合征模型大鼠骨骼肌NOS及NO的影响

目的：研究L3横突综合征模型大鼠损伤局部软组织NOS活性及NO含量与软组织损伤程度的关系,并观察针刀干预后的影响。方法：成年雄性SD大鼠128只随机分为正常组、模型组、氨基胍组、针刀组,每组32只。建立L3横突综合征动物模型,造模后14d,对造模局部软组织的硬结和条索状物无菌条件下用一次性针刀行纵行切割3刀,横行切割1刀,随即出针刀。氨基胍组从造模14d开始,按50mg/kg剂量经腹膜内给药,2次/d,直至处死前一天为止。通过针刀、氨基胍干预后在1、3、7、14d检测各组L3横突周围软组织NOS活性、NO含量及观察组织形态学变化。结果：①模型组iNOS活性及NO含量比正常组明显升高（F=522.860,P〈0.01）,针刀组、AG组比模型组明显降低（FiNOS=28.894,P〈0.01）,且各组iNOS活性及NO含量与损伤局部炎症反应及组织损伤程度相一致。②模型组、针刀组eNOS阳性表达增强,7d达到峰值,针刀组与模型组比较差异有统计学意义（FeNOS=3.454,P〈0.05）。③模型组、氨基胍组、针刀组nNOS阳性表达较高,组间比较无统计学意义（FnNOS=0.962,P〉0.05）。结论：针刀干预后可明显抑制高浓度NO的生成,减轻损伤软组织炎症反应和损伤程度,改善微循环,防止病理性瘢痕组织的形成,对慢性软组织损伤动物模型有明显的促修复作用。     

The effect of aminoguanidine on the blood-retinal barrier in streptozocin-induced diabetic rats.

The effect of aminoguanidine hydrochloride (AG) on the blood-retinal barrier was studied in rats with streptozocin-induced diabetes. Half of the rats were given AG (100 mg/kg/day) while the remainder received no treatment. Vitreous fluorophotometry was performed on all rats before STZ injection and 2 weeks after induction of diabetes mellitus. Two weeks after STZ injection the mean 60-minute vitreous fluorescein concentration following dye injection had increased more in the nontreated group than in the AG-treated group, suggesting that AG may have some beneficial effect on the breakdown of the blood-retinal barrier.     

Peri-ischemic aminoguanidine fails to ameliorate neurologic and histopathologic outcome after transient spinal cord ischemia.

Inhibition of neurotoxic events that lead to delayed cellular damage may prevent motor function loss after transient spinal cord ischemia. An important effect of the neuroprotective substance aminoguanidine (AG) is the inhibition of inducible nitric oxide synthase (iNOS), a perpetrator of focal ischemic damage. The authors studied the protective effects of AG on hind limb motor function and histopathologic outcome in an experimental model for spinal cord ischemia, and related these findings to the protein content of iNOS in the spinal cord. Temporary spinal cord ischemia was induced by 28 minutes of infrarenal balloon occlusion of the aorta in 40 anesthetized New Zealand White rabbits. Animals were assigned randomly to two treatments: saline (n = 20) or AG (n = 20; 100 mg/kg intravenously before occlusion). Postoperatively, treatment was continued with subcutaneous injections twice daily (saline or 100 mg/kg AG). Normothermia (38 degrees C) was maintained during ischemia, and rectal temperature was assessed before and after subcutaneous injections. Animals were observed for 96 hours for neurologic evaluation (Tarlov score), and the lumbosacral spinal cord was examined for ischemic damage after perfusion and fixation. Lastly, iNOS protein content was determined using Western blot analysis 48 hours after ischemia in five animals from each group. Neurologic outcome at 96 hours after reperfusion was the same in both groups. The incidence of paraplegia was 67% in the saline-treated group versus 53% in the AG-treated group. No differences in infarction volume, total number of viable motoneurons, or total number of eosinophilic neurons were present between the groups. At 48 hours after reperfusion, iNOS protein content in the spinal cord was increased in one animal in the AG-treated group and in three animals in the control group. The data indicate that peri-ischemic treatment with high-dose AG in rabbits offers no protection against a period of normothermic spinal cord ischemia. There was no conclusive evidence of spinal cord iNOS inhibition after treatment with AG.