内皮一氧化氮合酶胞内定位作用蛋白的研究

内皮细胞一氧化氮合酶活性的调节是一系列影响其转录、翻译和翻译后因素的综合作用过程,其调节机制迄今尚未完全查明。内皮一氧化氮合酶的胞内定位调节是其翻译后调节的重要组成部分。近年来发现的几种蛋白,包括动力蛋白2、一氧化氮合酶相互作用蛋白以及一氧化氮合酶转运诱导蛋白与内皮一氧化氮合酶共存于内皮细胞中,介导一氧化氮合酶的胞内定位,从而影响内皮一氧化氮合酶的活性。

一氧化氮合酶和微血管形成与原发性肝癌发生发展的关系

【目的】研究诱导型一氧化氮合酶 (iNOS)在人原发性肝癌组织中的表达及其与肝癌微血管形成的关系。【方法】采用免疫组化S P法检测 4 5例原发性肝癌患者肝癌组织、癌旁组织及非癌组织中iNOS的表达 ,同时以抗CD34标记血管内皮细胞 ,检测微血管密度 (MVD) ,并分析其与肿瘤行为之间的关系。【结果】肝癌组织中iNOS阳性表达率为 77.8% ,MVD均值为 2 2 .9± 4 .8,显著高于癌周组织和正常肝组织。肝癌组织中iNOS的表达与MVD呈正相关。iNOS阳性表达组及高MVD值 (≥ 2 2 .9)组的 3年生存率均显著低于iN OS阴性表达组及低MVD值 (<2 2 .9)组 ,且差异有显著性 (P<0 .0 5 )。【结论】肝癌组织中iNOS高阳性表达及MVD值增加 ,两者呈正相关。iNOS的表达及MVD值可作为判断肝癌预后的重要指标。

卡托普利晚期预处理对人内皮细胞缺氧复氧损伤时内皮素1和一氧化氮合酶表达的影响

观察缺氧复氧损伤时内皮细胞表达内皮素、一氧化氮合酶和一氧化氮的变化 ,并探讨卡托普利晚期预处理对内皮细胞在缺氧复氧损伤时三者的影响及机制。选用体外培养的第 3代人脐静脉内皮细胞 ,设正常对照组、单纯缺氧组、缺氧复氧组、卡托普利预处理组、卡托普利 +缓激肽B2 受体阻断剂组、卡托普利 +蛋白激酶C阻断剂组和卡托普利 +核因子κB阻断剂组 ,然后提取总RNA ,运用半定量逆转录—聚合酶链反应检测内皮素、一氧化氮合酶的mRNA表达。并利用分光光度计检测总一氧化氮合酶和一氧化氮蛋白的表达。结果发现 ,内皮素的灰度值在单纯缺氧组、缺氧复氧组均升高 ,在卡托普利组降低 ,而在三种阻断剂组均升高 ;诱导型一氧化氮合酶和内皮型一氧化氮合酶灰度值的变化规律与内皮素相反 ,其中诱导型一氧化氮合酶的变化较为轻微。与对照组相比 ,单纯缺氧组和缺氧复氧组一氧化氮合酶和一氧化氮有不同程度的降低 (P <0 .0 1) ;与单纯缺氧组和缺氧复氧组相比 ,卡托普利组一氧化氮合酶和一氧化氮均明显升高 (P <0 .0 1) ;与卡托普利组相比 ,3种阻断剂均可使一氧化氮合酶和一氧化氮的表达下降 (P <0 .0 1) ,而与缺氧复氧组相比表达升高 (P <0 .0 1)。结果提示 ,缺氧复氧可以使内皮细胞表达的内皮素增加 ,一氧化氮合酶降低 ,

糖尿病大鼠骨质疏松与过氧亚硝基阴离子关系的免疫组化研究

目的:探讨过氧亚硝基阴离子(ONOO-)与糖尿病(DM)骨质疏松(OP)的关系。方法:用链脲佐菌素 (STZ)诱导糖尿病大鼠模型12周后,进行骨密度(BMD)检查、观察股骨胫骨形态学改变,应用免疫组化法检测骨中 和高糖溶液培养成骨细胞(OB)中的诱导型一氧化氮合酶(iNOS)、ONOO-水平的变化。结果:高糖溶液培养OB中的 iNOS和ONOO-升高;DM大鼠骨中的iNOS和ONOO-升高、BMD降低、骨形态学呈退行性改变。结论:骨中iNOS、 ONOO-增加可能是糖尿病OP的发病机制之一。

茶油清润合剂治疗小鼠便秘疗效观察及作用机制研究

目的观察茶油清润合剂治疗小鼠便秘疗效并探讨其作用机制。方法将72只小鼠随机均分为空白对照组、模型组、茶油清润合剂低中高剂量组、麻仁丸组。除空白组外,其余成模后分别予0.9%生理盐水、低中高剂量茶油清润合剂、麻仁丸灌胃给药3 d,最后测量肠内碳末推进率,检测SP、VIP、NOS-1表达并观察结肠组织病理变化。结果与空白组比较,模型组小鼠肠内碳末推进率降低、SP降低、VIP升高、NOS-1升高且差异均有统计学意义(P<0.01或P<0.05);与模型组比较,低中高剂量组及麻仁丸组小鼠碳末推进率均升高且差异均有统计学意义(P<0.01或P<0.05),低中高剂量组小鼠大肠SP均升高且差异均有统计学意义(P<0.01)、VIP均降低且差异均有统计学意义(P<0.05或P<0.01)、NOS-1均降低但差异均无统计学意义(P>0.05);低中高剂量组结肠组织病理变化较模型组有改善。结论茶油清润合剂治疗便秘疗效确切,其作用机制可能是通过增加肠SP、减少肠VIP、减少肠粘膜和粘膜下层局部水肿糜烂程度或炎性细胞数量、保持肠腺体规整以维护和促进肠道排便功能。

STEMI患者血清SAA1、NOS和MDA水平变化与PCI术后发生心室重塑的关系

目的探究ST段抬高型心肌梗死(STEMI)患者血清淀粉样蛋白A1(SAA1)、一氧化氮氧合酶(NOS)和丙二醛(MDA)水平变化与经皮冠状动脉介入治疗(PCI)术后发生心室重塑的关系。方法选取长沙市第三医院心血管内科于2019年5月至2021年5月收治的118例拟行PCI的STEMI患者作为疾病组,另选取同期118例健康体检者作为对照组,分别于PCI术前与体检当天采集静脉血,检测并对比两组患者血清SAA1、NOS和MDA水平。STEMI患者PCI术后均随访6个月,检查心室重塑相关指标[左心室收缩末期容积(LVESV)、左室舒张末期容积(LVEDV)、左心室射血分数(LVEF)、左心室质量指数(LVMI)],根据术后是否发生心室重塑将其分为心室重塑组与非心室重塑组,对比此两组患者血清SAA1、NOS、MDA水平及心室重塑相关指标。采用Pearson法分析血清SAA1、NOS、MDA水平与心室重塑指标的相关性;采用Logistic回归分析法分析STEMI患者PCI术后心室重塑的影响因素。结果疾病组血清SAA1、NOS、MDA水平高于对照组(P<0.05);PCI术后随访6个月,STEMI患者心室重塑发生率为29.66%;心室重塑组血清SAA1、NOS、MDA水平高于非心室重塑组(P<0.05),末次彩超检查时的LVMI、LVESV、LVEDV水平均高于非心室重塑组(P<0.05),LVEF水平低于非心室重塑组(P<0.05);Pearson相关分析显示,血清SAA1、NOS、MDA表达水平与LVMI、LVESV、LVEDV水平均呈正相关(P<0.05),与LVEF水平呈负相关(P<0.05);经Logistic回归分析发现,糖尿病史、病变血管支数、冠脉Gensini评分及血清SAA1、NOS、MDA高水平表达均是STEMI患者发生心室重塑的危险因素(P<0.05)。结论血清SAA1、NOS、MDA水平在STEMI患者中均异常高表达,增加STEMI患者PCI术后发生心室重塑的风险;糖尿病史、病变血管支数、冠脉Gensini评分是STEMI患者PCI术后发生心室重塑的危险因素,对临床具有重要的指导作用。

结肠康对恶唑酮诱导小鼠溃疡性结肠炎MPO、NO、iNOS的影响

目的观察中药复方结肠康(黄芪、白术、茯苓、延胡索、黄连、三七等)对恶唑酮诱导小鼠溃疡性结肠炎中髓过氧化物酶(MPO)活性、一氧化氮(NO)水平、诱导型一氧化氮合酶(iNOS)蛋白表达的影响,并探讨其治疗溃疡性结肠炎的作用机制。方法小鼠颈背部3%恶唑酮致敏2 d,第6天用1.5%恶唑酮灌肠,灌肠当日开始灌胃不同剂量结肠康。灌胃3 d后,处死小鼠,测定结肠组织MPO活性和NO水平,免疫组织化学检测iNOS蛋白表达。柳氮磺胺吡啶作为阳性对照药。结果与空白对照组相比,模型组MPO活性显著增加(P<0.01),NO水平、iNOS表达显著增加(P<0.01);结肠康(6.4、12.8、25.6 g/kg)组和柳氮磺胺吡啶(0.2 g/kg)组均能显著降低MPO活性、NO水平和iNOS蛋白表达(P<0.01);阳性对照药柳氮磺胺吡啶也有相似作用。结论中药复方结肠康对恶唑酮诱导小鼠溃疡性结肠炎MPO活性、NO水平、iNOS表达有一定的影响,对溃疡性结肠炎具有一定的治疗作用。

基于NF-κB iNOS-COX-2信号通路探究瑞芬太尼对脑缺血再灌注损伤大鼠神经功能的作用机制

目的研究基于核转录因子(NF)-κB-一氧化氮合酶(iNOS)-环氧合酶(COX)-2信号通路探究瑞芬太尼对脑缺血再灌注损伤大鼠神经功能的作用机制。方法选取清洁及健康雄性大鼠32只,8只为空白组,剩余24只建立脑缺血再灌注损伤模型,分为模型组、低、高剂量瑞芬太尼组各8只。采用Longa 5级神经功能缺损评分,评估神经功能损伤评分;酶联免疫吸附试验检测iNOS;采用色谱柱检测脑组织单胺类神经递质含量甲肾上腺素(NE)、多巴胺(DA)、5-羟色胺(HT);采用Western印迹检测NF-κB、iNOS、COX-2。结果与模型组相比,低、高剂量瑞芬太尼组神经功能损伤明显降低,神经递质NE、DA含量明显降低,5-HT明显升高,NO水平明显降低,iNOS、COX-2、NF-κB蛋白表达明显降低(均P<0.05)。结论瑞芬太尼通过调控NF-κB-iNOS-COX-2信号通路蛋白水平,改善大鼠脑缺血再灌注损伤的神经功能。

己酮可可碱对内毒素诱导大鼠急性肺损伤的干预作用

目的:观察己酮可可碱(PTX)对内毒素(LPS)诱导急性肺损伤(ALI)大鼠模型各项病理生理和生化指标的影响,探讨PTX对ALI的干预阻断作用.方法:将72只月龄和体质量相近的雄性SD大鼠随机分为3组:对照组(NS组),实验组(LPS组),治疗组(PTX组),每组24只.给予对照组大鼠尾静脉注射生理盐水,实验组大鼠尾静脉内注射LPS4mg/kg,治疗组大鼠尾静脉注射LPS前1h,由腹腔注射0.036mol/LPTX10mg/kg.确认实验组复制ALI模型成功之后,即刻给予PTX10mg/kg腹腔注射,间隔1h重复给药,连续5次;其余两组大鼠与实验组同样时间间隔给予腹腔注射等容积的生理盐水.测定各组动脉血氧分压(PaO2),pH值,二氧化碳分压(PaCO2),肺系数,肺水含量,肺通透性指数,检测支气管肺泡灌洗液中性白细胞及巨噬细胞比例,检测丙二醛(MDA),超氧化物歧化酶(SOD),一氧化氮(NO),诱生性一氧化氮合成酶(iNOS)含量,并进行肺组织大体,病理形态学观察.结果:治疗组与实验组相比,PaO2和pH值升高,PaCO2降低,肺系数(0.59±0.17 vs 0.92±0.11,P<0.05),肺含水量(84.46±0.39 vs 80.22±0.37,P<0.05),肺通透性指数(7.28±0.54 vs 12.32±0.28,P<0.05)均有明显下降;肺泡灌洗液中性粒白细胞比例下降,肺通透指数减低,NO,iNOS明显下降,SOD水平显著升高(P<0.05).病理学观察治疗组肺组织病变较实验组为轻.结论:PTX对LPS诱导ALI大鼠模型具有保护作用,其机制可能与PTX改善能量代谢及减少局部细胞毒性物质有关.PTX对由LPS诱导的ALI具有一定保护作用.

非诺贝特对LPC诱导的脐静脉内皮细胞NO及eNOS基因表达的影响

【目的】探讨非诺贝特对LPC诱导的脐静脉内皮细胞一氧化氮(NO)及内皮型一氧化氮合酶(eNOS)基因表达的影响。【方法】体外培养人脐静脉内皮细胞(HUVECs),分为:①正常对照组;②溶血卵磷脂(LPC)组;③低浓度非诺贝特组(10μmol/L);④中浓度非诺贝特组(50μmol/L);⑤高浓度非诺贝特组(100μmol/L)。采用实时定量PCR(real-time PCR)及流式细胞仪(FCM)分别观测LPC对内皮细胞eNOS mRNA及蛋白表达的影响,采用硝酸还原酶法测定NO含量,并观测非诺贝特干预后的变化。【结果】与正常对照组比较,LPC使HUVEC eNOS mRNA及蛋白表达降低,NO合成减少。非诺贝特可干预LPC对内皮细胞的作用,使eNOS mRNA及蛋白表达升高,NO合成增加,且其作用呈时间-效应、浓度-效应依赖关系。【结论】非诺贝特可改善LPC对HUVECs的影响,使内皮细胞eNOS mRNA及蛋白表达升高,NO合成增加,从而起到抗动脉硬化作用。

Effects of melatonin on the expression of iNOS and COX-2 in rat models of colitis

AIM: To investigate the effects of melatonin (MT) on the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in rat models of colitis.METHODS: Healthy adult Sprague-Dawlay (SD) rats of both sexes, weighing 280±30 g, were employed in the present study. The rat models of colitis were induced by either acetic acid or 2,4,6-trinitrobenzene sulfonic acid (TNBS) enemas. The experimental animals were randomly divided into melatonin treatment and model control group that were intracolicly treated daily with melatonin at doses of 2.5, 5.0, 10.0 mg.kg-1 and equal amount of saline respectively from 24 h following induction of colitis in rats inflicted with acetic acid enema and the seventh day in rats with TNBS to the end of study. A normal control group of rats treated with neither acetic acid nor TNBS but saline enema was also included in the study. On the 28th day of the experiment, the rat colon mucosal damage index (CDMI) was calculated, and the colonic prostaglandin E2(PGE2), nitric oxide (NO), as well as the iNOS and COX-2expression were also determined biochemically or immunohistochemically.RESULTS: CDMI increased to 2.87±0.64 and 3.12±1.12respectively in rats treated with acetic acid and TNBS enema,which was in accordance with the significantly elevated colonic NO and PGE2 contents, as well as the up-regulated colonic iNOS and COX-2 expression in both of the two rat models of colitis. With treatment by melatonin at the doses of 5.0 and 10.0 mg@kg-1, CDMI in both models of rat colitis was significantly decreased (P＜0.05-0.01), which accorded synchronously and unanimously with the reduced colonic NO and PGE2 content, as well as the down-regulated expression of colonic iNOS and COX-2.CONCLUSION: Melatonin has a protective effect on colonic injury induced by both acetic acid and TNBS enemas, which is probably via a mechanism of local inhibition of iNOS and COX-2 expression in colonic mucosa.

Inducible heat shock protein 70 kD and inducible nitric oxide synthase in hemorrhage/resuscitation-induced injury

Inducible heat shock protein 70 kD (HSP-70i) has been shown to protect cells, tissues, and organs from harmful assaults in in vivo and in vitro experimental models. Hemorrhagic shock followed by resuscitation is the principal cause of death among trauma patients and soldiers in the battlefield. Although the underlying mechanisms are still not fully understood, it has been shown that nitric oxide (NO) overproduction and inducible nitric oxide synthase (iNOS) overexpression play important roles in producing injury caused by hemorrhagic shock including increases in polymorphonuclear neutrophils (PMN) infiltration to injured tissues and leukotriene B4 (LTB4) generation. Moreover, transcription factors responsible for iNOS expression are also altered by hemorrhage and resuscitation. It has been evident that either up-regulation of HSP-70i or down-regulation of iNOS can limit tissue injury caused by ischemia/reperfusion or hemorrhage/resuscitation. In our laboratory, geldanamycin, a member of ansamycin family, has been shown to induce HSP-70i overexpression and then subsequently to inhibit iNOS expression, to reduce cellular caspase-3 activity, and to preserve cellular ATP levels. HSP-70i is found to couple to iNOS and its transcription factor. Therefore, the complex formation between HSP-70i and iNOS may be a novel mechanism for protection from hemorrhage/resuscitation-in-duced injury.

Polypeptide from Chlamys farreri inhibits UVB-induced apoptosis of HaCaT cells via iNOS/NO and HSP90

Polypeptide from Chlamys farreri(PCF) is a novel marine bioactive product that was isolated from the gonochoric Chinese scallop Chlamys farreri,and was found to be an effective antioxidant in our recent studies.In this study,we investigated the effect of PCF on ultraviolet B(UVB)-induced apoptosis of HaCaT cells and the intracellular signaling pathways involved.Pretreatment with the inducible nitric oxide synthase(iNOS) inhibitor S-methylisothiourea sulfate inhibited UVB-induced apoptosis,indicating that iNOS and NO play important roles in apoptosis.On the other hand,the inhibition of UVB-induced apoptosis in the immortalized keratinocyte(HaCaT) cells by PCF was estimated using a DNA ladder.PCF treatment inhibited UVB-induced iNOS activation,as determined by RT-PCR,NO production,as determined by ESR,and up-regulated heat shock protein(HSP) 90 activation,as determined by Western blotting.Our results indicate that iNOS and NO are involved in UVB-induced apoptosis of HaCaT cells and the protective effect of PCF against UVB irradiation is exerted by suppressing the expression of iNOS,followed by inhibition of NO release and enhanced activation of HSP90.

Cross-talk between calcium-calmodulin and nitric oxide in abscisic acid signaling in leaves of maize plants

Using pharmacological and biochemical approaches, the signaling pathways between hydrogen peroxide （H2O2）, calcium （Ca^2＋）-calmodulin （CAM）, and nitric oxide （NO） in abscisic acid （ABA）-induced antioxidant defense were investigated in leaves of maize （Zea mays L.） plants. Treatments with ABA, H2O2, and CaCl2 induced increases in the generation of NO in maize mesophyll cells and the activity of nitric oxide synthase （NOS） in the cytosolic and microsomal fractions of maize leaves. However, such increases were blocked by the pretreatments with Ca^2＋ inhibitors and CaM antagonists. Meanwhile, pretreatments with two NOS inhibitors also suppressed the Ca^2＋-induced increase in the production of NO. On the other hand, treatments with ABA and the NO donor sodium nitroprusside （SNP） also led to increases in the concentration of cytosolic Ca^2＋ in protoplasts of mesophyll cells and in the expression of calmodulin 1 （CaM1） gene and the contents of CaM in leaves of maize plants, and the increases induced by ABA were reduced by the pretreatments with a NO scavenger and a NOS inhibitor. Moreover, SNP-induced increases in the expression of the antioxidant genes superoxide dismutase 4 （SOD4）, cytosolic ascorbate peroxidase （cAPX）, and glutathione reductase 1 （GR1） and the activities of the chloroplastic and cytosolic antioxidant enzymes were arrested by the pretreatments with Ca^2＋ inhibitors and CaM antagonists. Our results suggest that Ca^2＋-CaM functions both upstream and downstream of NO production, which is mainly from NOS, in ABA- and H2O2-induced antioxidant defense in leaves of maize plants.

Gender differences in hepatic ischemic reperfusion injury in rats are associated with endothelial cell nitric oxide synthase-derived nitric oxide

AIM: This study was designed to examine the hypothesis that gender differences in I/R injury are associated withendothelial cell nitric oxide synthase (eNOS)-derived nitric oxide (NO).METHODS: Wistar rats were randomized into seven experimental groups (12 animals per group). Except for the sham operated groups, all rats were subjected to total liver ischemia for 40 min followed by reperfusion. All experimental groups received different treatments 45 min before the laparotomy. For each group, half of the animals (six) were used to investigate the survival; blood samples and liver tissues were obtained in the remaining six animals after 3 h of reperfusion to assess serum NO, alanine aminotransferase (ALT) and TNF-α levels, liver tissuemalondialdehyde (MDA) content, and severity of hepatic I/R injury.RESULTS: Basal serum NO levels in female sham operated (FS) group were nearly 1.5-fold of male sham operated (MS) group (66.7±11.0 μmol/L vs 45.3±10.1μmol/L, P＜0.01). Although serum NO levels decreased significantly after hepatic I/R (P＜0.01, vs sham operated groups), they were still significantly higher in female rat (F) group than in male rat (M) group (47.8±8.6 μmol/L vs 23.8±4.7 μmol/L, P＜0.01). Serum ALT and TNF-α levels, and liver tissue MDA content were significantly lower in F group than in M group (370.5±46.4 U/L, 0.99±0.11 μg/L and 0.57±0.10 μmol/g vs668.7±78.7 U/L, 1.71±0.18 μg/Land 0.86±0.11 μmol/g, respectively, P＜0.01). I/R induced significant injury to the liver both in M and F groups (P＜0.01 vs sham operated groups). But the degree of hepatocyte injury was significantly milder in F group than in M group (P＜0.05 and P＜0.01). The median survival time was six days in F group and one day in M group. The overall survival rate was significantly higher in F group than in M group (P＜0.05). When compared with male rats pretreated with saline (M group), pretreatment of male rats with 17-β- estradiol (E2) (M+E2 group) significantly increased serum NO levels and significantly decreased serum ALT and TNF-α levels, and liver tissue MDA content after I/R (P＜0.01).The degree of hepatocyte injury was significantly decreased and the overall survival rate was significantly improved in M+E2 group than in M group (P＜0.01 and P＜0.05). TheNOS inhibitor Nw-nitro-L-arginine methyl ester (L-NAME) treatment could completely abolish the protective effects of estrogen in both male and female rats. CONCLUSION: The protective effects afforded to female rats subjected to hepatic I/R are associated with eNOSderived NO.

Aminoguanidine impedes human pancreatic tumor growth and metastasis development in nude mice

AIM:To study the action of aminoguanidine on pancreatic cancer xenografts in relation to cell proliferation,apoptosis,redox status and vascularization.METHODS:Xenografts of PANC-1 cells were developed in nude mice. The animals were separated into two groups:control and aminoguanidine treated. Tumor growth,survival and appearance of metastases were determined in vivo in both groups. Tumors were excised and ex vivo histochemical studies were performed. Cell growth was assessed by Ki-67 expression. Apoptosis was studied by intratumoral expression of B cell lymphoma-2 protein (Bcl-2) family proteins and Terminal deoxynucleotidyl transferase biotin-dUTP Nick End Labeling (Tunel). Redox status was evaluated by the expression of endothelial nitric oxide synthase (eNOS),catalase,copper-zinc superoxide dismutase (CuZnSOD),manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPx). Finally,vascularization was determined by Massons trichromic staining,and by VEGF and CD34 expression.RESULTS:Tumor volumes after 32 d of treatment by aminoguanidine (AG) were significantly lower than in control mice (P < 0.01). Median survival of AG mice was significantly greater than control animals (P < 0.01). The appearance of both homolateral and contralateral palpable metastases was significantly delayed in AG group. Apoptotic cells,intratumoral vascularization (trichromic stain) and the expression of Ki-67,Bax,eNOS,CD34,VEGF,catalase,CuZnSOD and MnSOD were diminished in AG treated mice (P < 0.01),while the expression of Bcl-2 and GPx did not change.CONCLUSION:The antitumoral action of aminoguanidine is associated with decreased cell proliferation,reduced angiogenesis,and reduced expression of antioxidant enzymes.

NITRIC OXIDE SYNTHESIS IN MYOCARDIUM FOLLOWING BURN INJURY IN RATS

The nitric oxide and cyclic GMP production in myocardium early after burn injury in rats were investi- gated. Nitric oxide synthase activity was measured in cytosols from the left ventricular wall of burned rats. Cytosols from the control group animals were shown to contain mainly Ca2+ dependent nitric oxide synthase （cNOS） with small amount of Ca2+ independent nitric oxide synthase （iNOS）. Following burn injury, there was a marked increase in iNOS activity with a peak at sh post-burn, however, myocardial cNOS ac- tivity was found to decline obviously. Parallel to iNOS induction there was a significant increase in myocar- dial nitric oxide and cyclic GMP production. All these changes were alleviated by treatment of the rats with dexamethasone. Since increases in cyclic GMP levels in the heart were associated with reduced myocardial contractility, it is possible that enhanced production of nitric oxide by a Ca2+, independent NO synthase ac- counts, at least in part, for the depression of myocardial contractility seen in burn animals and patients.

辛伐他汀、氨氯地平对实验性兔动脉粥样硬化进程中NOS/NO系统的影响

目的探讨诱导型一氧化氮合酶(iNOS)-一氧化氮(NO)系统在动脉粥样硬化进程中的变化、相互关系及辛伐他汀、氨氯地平对动脉粥样硬化进程中iNOS-NO的影响。方法 24只家兔予以高胆固醇饮食8周,8周后随机分为三组(n=8),三组均停用高胆固醇饮食,改普通饮食8周;模型组不用干预,另外两组分别喂饲辛伐他汀及氨氯地平进行药物干预。另取8只家兔予以普通饮食16周作为对照组。结果与对照组比较,模型组血脂水平明显升高,血清NO含量明显降低,iNOS表达明显升高(P均<0.01)。与模型组比较辛伐他汀组血浆TC、TG、LDL-C、ox-LDL-C下降明显(P<0.01),HDL-C升高(P<0.01);血清NO含量明显升高(P<0.01),iNOS表达明显减少(P<0.05)。而氨氯地平组血脂水平与模型组比较无统计学差异(P>0.05);血清NO含量亦无统计学差异(P>0.05),但iNOS表达明显减少(P<0.05)。结论动脉粥样硬化进程中,辛伐他汀、氨氯地平均可以通过下调血红素加氧酶/NO系统而延缓动脉粥样硬化进程。

益元起痿丸治疗糖尿病性勃起功能障碍大鼠作用机制

目的观察益元起痿丸对糖尿病性勃起功能障碍(DMED)大鼠的治疗作用,并探讨其对一氧化氮(NO)/环磷酸鸟苷(cGMP)信号通路的调控作用。方法55只2~3月龄清洁级、健康SD雄鼠腹腔注射链脲佐菌素(STZ)建立DMED大鼠模型,另取10只2~3月龄清洁级、健康SD雄鼠记为正常组;建模成功后随机分组,西地那非组予以西地那非5 mg·kg^(-1)灌胃,益元起痿丸低、中、高剂量组予以1.5、3.0、6.0 g·kg^(-1)益元起痿丸灌胃,模型组与正常组均予以生理盐水灌胃,各10 mL·kg^(-1),每天1次,共2个月。干预后,采用压力检测系统测定各组大鼠的阴茎勃起功能;苏木素-伊红(HE)染色观察阴茎海绵体病理变化,透射电镜观察大鼠阴茎海绵体超微结构;硝酸还原酶法检测阴茎海绵体组织NO水平,酶联免疫吸附测定法(ELISA)检测cGMP及晚期糖基化总产物(AGEs)水平;实时荧光定量聚合酶链式反应(Real-time PCR)检测大鼠阴茎组织内皮型一氧化氮合成酶(eNOS)、神经源型一氧化氮氧合酶(nNOS)、总一氧化氮氧合酶(NOS)、5型磷酸二酯酶(PDE5)信使核糖核酸(mRNA)表达;蛋白免疫印迹法(Western blot)检测上述蛋白表达。结果与正常组比较,模型组大鼠阴茎海绵窦内压(ICP),阴茎海绵体组织NO、cGMP含量及nNOS、NOS mRNA和蛋白表达均降低,PDE5 mRNA和蛋白表达均升高,上述差异均有统计学意义(P<0.05);与模型组比较,西地那非组、益元起痿丸低、中、高剂量组ICP,阴茎海绵体组织NO、cGMP含量及nNOS、NOS mRNA和蛋白表达均升高,PDE5 mRNA和蛋白表达均降低(P<0.05)。正常组阴茎海绵体组织及细胞超微结构均未见病理改变,模型组有严重病理改变,西地那非组、益元起痿丸各剂量组均较模型组改善,且益元起痿丸高剂量组病理改变更轻更佳。结论益元起痿丸可以改善DMED大鼠阴茎勃起功能,减轻阴茎海绵体病理损伤,作用机制可能与促进nNOS、NOS表达,抑制PDE5表达,激活NO/cGMP信号通路有关。