选择性抑制一氧化氮合酶对大鼠小体积肝移植的影响

目的:探讨诱导性一氧化氮合成酶(iNOS)在大鼠小体积肝移植模型中的作用?方法:选取清洁雄性Spraque-Dawley大鼠90只?采用改良的二袖套法建立吻合肝动脉的小移植物模型?实验分为3组:正常对照组?小体积肝移植组和氨基胍(AG)注射组?术后分别在1?3? 6?12 h等4个时间点处死5只大鼠并采取部分肝组织及血清样本?检测指标:血清丙氨酸转氨酶(ALT),实时荧光定量RT-PCR 测定肝组织iNOS mRNA 的表达,免疫组化法测定肝组织iNOS 蛋白的表达,HE染色光镜下病理观察等?结果:AG组与小体积肝移植组相比,实时荧光定量PCR显示:肝组织中iNOS mRNA 表达量明显下降(P < 0.05,n = 5);免疫组化显示:肝组织中iNOS 蛋白表达下降;但ALT 明显升高(P < 0.05,n = 5);病理显示肝细胞大量坏死?结论:AG 能抑制iNOS 在大鼠小体积模型中的表达,但不能减轻肝脏损伤,反而加重了损伤?     

iNOS在复发性翼状胬肉中的表达及意义

目的：检测诱导型一氧化氮合酶（iNOS）在复发性翼状胬肉组织中的表达水平,初步探讨iNOS在翼状胬肉复发过程的作用机制.方法：应用SP免疫组织化学染色法检测5例正常结膜组织、6例原发性翼状胬肉组织及22例复发性翼状胬肉组织中iNOS的免疫学定位及表达,分析iNOS在正常结膜、原发性翼状胬肉及复发性翼状胬肉中的表达差异.结果：iNOS在正常结膜组织、原发性翼状胬肉组织及复发性翼状胬肉组织的表达组间差异有统计学意义,P＜0.05.结论：iNOS在复发性翼状胬肉中呈高表达,提示iNOS能促进新生血管形成,可能与翼状胬肉术后复发有关.     

雄激素对大鼠脑缺血/再灌注损伤后脑内顶叶皮层eNOS及iNOS表达的影响

目的探讨雄激素对大鼠脑缺血/再灌注（I/R）损伤后,脑内内皮型一氧化氮合酶（eNOS）和诱生型一氧化氮合酶（iNOS）表达的影响。方法将大鼠45只随机均分为去势组、雄激素组和假手术组,喂养2周后,各组再按照I/R后不同时间点分为6,24和72 h 3个亚组,共9组,每组均5只。采用W estern b lot检测不同处理组脑内顶叶皮层中eNOS和iNOS表达的变化。结果随着再灌注时间的延长,各组大鼠eNOS的表达水平均有下降的趋势;而去势组和假手术组大鼠iNOS表达的水平均有上升的趋势。与假手术组相比,再灌注各时间点雄激素处理组eNOS的水平显著升高（P<0.01）,去势组大鼠eNOS的水平明显降低（P<0.05）。而iNOS的表达水平则呈现出相反的趋势:即雄激素处理组明显低于正常水平（P<0.05）;而去势组大鼠则显著升高（P<0.05）。结论脑I/R后,在雄激素存在的情况下,eNOS的表达水平升高,而iNOS的表达水平降低;去势组eNOS的表达水平下降,而iNOS的表达水平上升,提示雄激素对脑I/R损伤可能具有保护作用。     

肝癌中iNOS与P16、Bax的表达及其与细胞凋亡关系

探讨在肝癌(HCC)中一氧化氮合酶(iNOS)的表达对P16、Bax表达的影响及其与细胞凋亡的关系。采用免疫组化方法对HBsAg均阳性的98例HCC患者的iNOS、P16、Bax表达进行分析，TUNEL法检测细胞凋亡。iNOS和加以棕黄色颗粒着色于细胞质和／或细胞膜中，细胞核阴性，间质细胞着色不明显。P16以棕黄色着色于细胞核中，细胞质中偶见。细胞凋亡为细胞核着色，细胞质阴性。P16、Bax的表达及细胞的凋亡率与iNOS的表达有关。iNOS的表达可诱导抑癌基因P16、Bax的表达和细胞凋亡的发生，从而影响Hcc分化。故在诱导Hcc中iNOS的表达，有望提高肝细胞癌的临床效果。     

U0126对谷氨酸神经毒性损伤模型大鼠的脑保护作用

目的 探索U0126对脑组织谷氨酸神经毒性的保护作用及可能机制。方法 健康成年雄性SD大鼠皮层注射 N-甲基-D-天冬氨酸（NMDA）建立脑组织谷氨酸神经毒性模型。首先,采用不同浓度 NMDA（50、100、200mmol/L）及处理不同时间（3、6、12、24 h）筛选最佳的建模条件。根据选定的最佳条件,实验设对照组、MAPK/ERK1/2抑制剂U0126单独处理组（2 g/L）、NMDA组（200 mmol/L）、不同浓度（0.5、1、2 g/L）U0126联合NMDA处理组。各组处理24 h后处死动物,脑组织切片后行HE染色组织评价损伤;蛋白质印迹法检测损伤部位环氧合酶-2（COX-2）、诱导型一氧化氮合酶（iNOS）、Caspase-3（活化形式）及磷酸化ERK1/2（p-ERK1/2）表达水平,确定U0126在脑组织谷氨酸神经毒性损伤中的保护作用。结果 （1）NMDA以时间和浓度依赖的方式导致大鼠皮层兴奋毒性损伤,激活MAPK/ERK1/2信号通路,加重脑组织损伤,选取200 mmol/L NMDA处理24 h进行建模。（2）与对照组相比,NMDA组脑损伤部位COX-2、iNOS、Caspase-3（活化形式）、p-ERK1/2表达明显增加。U0126+NMDA处理组与NMDA组相比,COX-2、NOS、Caspase-3（活化形式）、p-ERK1/2表达水平随U0126浓度升高而降低,脑损伤的面积显著减小。结论 U0126对大鼠皮层谷氨酸神经毒性损伤具有保护作用,其机制可能与抑制ERK1/2激活及其下游的炎症、凋亡信号途径有关。     

孕三烯酮对子宫内膜异位症大鼠血清中iNOS作用的研究

目的观察孕三烯酮对子宫内膜异位症（EMs）大鼠模型血清诱导型一氧化氮合酶（iNOS）的影响。方法采用自体子宫内膜移植法建立EMs大鼠模型,造模成功者随机分为模型组、孕三烯酮组,分别灌胃给药,4周后择动情期处死。采用比色法检测血清iNOS活性。结果模型组与孕三烯酮组相比较,血清中iNOS明显降低,差异有统计学意义（P〈0.01）。结论孕三烯酮能降低EMs大鼠血清中iNOS活性,从而降低NO水平,抑制异位内膜的种植、生长。     

Advanced glycation endproducts and their receptor RAGE in Alzheimer's disease

Alzheimer's disease (AD) is the most common dementing disorder of late life. Although there might be various different triggering events in the early stages of the disease, they seem to converge on a few characteristic final pathways in the late stages, characterized by inflammation and neurodegeneration. In this review, we revisit the hypothesis that advanced glycation endproducts (AGEs) and their receptor RAGE may play an important role in disease pathogenesis. Accumulation of AGEs in cells and tissues is a normal feature of aging, but is accelerated in AD. In AD, AGEs can be detected in pathological deposits such as amyloid plaques and neurofibrillary tangles. AGEs explain many of the neuropathological and biochemical features of AD such as extensive protein crosslinking, glial induction of oxidative stress and neuronal cell death. Oxidative stress and AGEs initiate a positive feedback loop, where normal age-related changes develop into a pathophysiological cascade. RAGE and its decoy receptor soluble RAGE, may contribute to or protect against AD pathogenesis by influencing transport of β-amyloid into the brain or by manipulating inflammatory mechanisms. Targeted pharmacological interventions using AGE-inhibitors, RAGE-antagonists, RAGE-antibodies, soluble RAGE or RAGE signalling inhibitors such as membrane-permeable antioxidants may be promising therapeutic strategies to slow down the progression of AD.     

Nitric oxide in enteric nervous system mediated the inhibitory effect of vasopressin on the contraction of circular muscle strips from colon in male rats

Background Arginine vasopressin (AVP) is widely used in the treatment of critical diseases with hypotension, but the reports about its effect on gastrointestinal motility are controversial. The purpose of this study was to characterize the role of AVP in the regulation of colonic motility and the underlying mechanism. Methods The contraction of the circular muscle strips (CM) of colon in male rats was monitored by a polygraph. The expressions of cytoplasmic inducible nitric oxide synthase (iNOS), I‐κB, and the nuclear P65 in proximal colon were measured by Western blot. The V₁ receptors (V₁Rs) and iNOS were localized by immunohistochemistry. The content of nitric oxide (NO) in the colon was measured by Griess reagent at the absorbance of 560 nm. Key Results Arginine vasopressin (10^?10–10^?6 mol L^?1) caused a concentration‐dependent inhibition on CM contraction. Pretreatment with one of the following chemicals, including V‐1880 (10^?7 mol L^?1), TTX (10^?5 mol L^?1), l ‐NAME (10^?4 mol L^?1), NPLA (10^?7 mol L^?1), SMT (10^?3 mol L^?1), and PDTC (10^?3 mol L^?1), attenuated the inhibitory effect of AVP on CM contraction. Arginine vasopressin increased the expression of iNOS and the content of NO in proximal colon. These effects were attenuated by pretreatment with PDTC (10^?3 mol L^?1). Following AVP administration, the amount of cytoplasmic I‐κB decreased, but that of nuclear P65 increased. Double immunofluorescence labeling revealed that V₁Rs and iNOS were co‐localized on the cells of myenteric plexus in proximal colon. Conclusions & Inferences Arginine vasopressin inhibited the contraction of CM in proximal colon. This effect was mediated by NO produced from NF‐κB–iNOS pathway and neuronal NOS activation in myenteric plexus.     

粉防己碱对脂多糖诱导下RAW264.7细胞COX-2/PGE2、iNOS/NO表达的影响

本实验旨在观察粉防己碱（Tet）对脂多糖（LPS）诱导下RAW264.7细胞炎症模型的抗炎作用。采用 LPS 1 μg/mL刺激生长良好的RAW264.7巨噬细胞建立细胞炎症模型。在不同浓度Tet（1×10^-8,1×10^-7,1×10^-6mol/L）作用下,用Western blotting检测各组细胞中环加氧酶-2（COX-2）和诱导性一氧化氮激酶（iNOS）的表达,用NO检测试剂盒检测细胞培养液中NO的含量,酶免疫分析法检测培养液中前列腺素E₂（PGE₂）含量。结果显示Tet剂量依赖性地抑制LPS诱导的RAW264.7细胞PGE₂、NO的表达,同时抑制其合成酶COX-2和iNOS的表达。表明Tet具有抑制LPS诱导的RAW264.7细胞炎症反应的作用,其抗炎机制可能通过抑制COX-2、iNOS的表达,从而抑制其下游炎性介质NO、PGE₂的表达有关。