缺氧性肺动脉高压时一氧化氮合酶、左旋精氨酸及亚硝基左旋精氨酸甲酯的研究

目的研究一氧化氮（ＮＯ）在缺氧性肺动脉高压（ＨＰＨ）发病中的作用。方法用烟酰胺腺嘌呤二核苷酸磷酸—黄递酶（ＮｉｃｏｔｉｎａｍｉｄｅＡｄｅｎｉｎｅＤｉｎｕｃｌｅｏｔｉｄｅＰｈｏｓｐｈａｔｅＤｉａｐｈｏｒａｓｅ，ＮＡＤＰＨｄ）和免疫组化ＡＢＣ方法检测原生型和诱生型一氧化氮合酶（ｃＮＯＳ、ｉＮＯＳ）在正常和缺氧大鼠肺内的表达和分布，同时观察左旋精氨酸（Ｌａｒｇ）和亚硝基左旋精氨甲酯（ＬＮＡＭＥ）对正常和缺氧大鼠肺循环的影响。结果ＨＰＨ组，ＮＡＤＰＨｄ阳性反应见于大血管内皮、平滑肌、支气管粘膜上皮及小血管内皮和平滑肌中，而后者在正常时未见阳性反应；ｃＮＯＳ在肺血管内皮和支气管粘膜上皮中的表达明显减弱，甚至消失，而正常时不表达ｉＮＯＳ的肺血管内皮和血管、支气管平滑肌在ＨＰＨ组出现了阳性表达；缺氧时补充Ｌａｒｇ和ＬＮＡＭＥ，与单纯缺氧相比，对右心室肥大和肺血管重建无影响。结论缺氧时ｃＮＯＳ被抑制，可能对ＨＰＨ的形成具有一定的作用；而ｉＮＯＳ的诱导表达，则可能对ＨＰＨ的形成具有阻止作用。     

Expression of inducible nitric oxide synthase induced by lipid-associated membrane proteins of Ureaplasma urealyticum is regulated by nuclear factor κB-mediated mechanism in murine macrophages

U.urealyticumisthesmallestprokaryoticorgan ismcapableofself replication.Thetinymicroor ganismcouldbeisolatedfromurogenital,placen tasandtherespiratorytractsofpreterminfants.Moreover,U.urealyticuminfectionmaybein volvedinnon specificurethritis(NSU),prostati tis,postpartumfever,infertility,pelvicinflamma torydisease,neonatalpneumoniaandevenchronic lungdisease(CLD)[1].ItisknownthatU.urealyticumlackscellwallstructureandcontains abundantmembraneproteins,butitspathogenicity isstillunknownclearly.…     

大鼠大脑皮质微血管的一氧化氮合酶神经元及终末的正常分布研究

目的;研究正常大鼠大脑皮质额、顶、枕、颞叶的一氧化氮合酶（nitric oxide synthase,NOS）神经元及NOS阳性终末的分布,尤其注意它们与皮质微血管的关系。方法:采用NADPH-d组化方法。结果:NOS阳性神经元在皮质各层散在分布,数量较少,额、顶叶约半数的NOS神经元直接与皮质血管构成接触,枕、额叶中约三分之一的NOS神经元与皮质血管构成接触。而NOS阳性纤维多且密集成网状,额、顶叶的终末数量明显多于枕、颞叶,其中6％～7％的阳性终末分布至血管壁。结论:大脑皮质内的NOS神经元及NOS阳性终末参与皮质微循环的调节。     

Androgen receptor independent cardiovascular action of the antiandrogen flutamide

We have previously shown that flutamide (specific antagonist of the androgen receptor) has antihypertensive effects. In the present study we examined the mechanisms of flutamide action in the vasculature. The vascular effects of flutamide were assayed in aortae isolated from male or female Sprague-Dawley rats and from rats or mice lacking a functional androgen receptor ( tfm, testicular feminization mutation). The effect of flutamide on coronary flow was tested in isolated hearts. In addition, male hypertensive rats with tfm mutation were treated with flutamide, and blood pressure was monitored. Flutamide induced a relaxation of rat aortae from all the strains used (maximum relaxation at 10 microM: 51.3+/-5.2% of phenylephrine contraction) and increased the coronary flow. The aortic relaxation to flutamide was abolished by endothelium removal, or by inhibition of nitric oxide synthase, guanylyl cyclase, and tyrosine kinase but not by calmodulin inhibition. Flutamide treatment attenuated the development of hypertension in mouse renin transgenic rats with the tfm mutation. Flutamide produces direct vasodilation by inducing release of NO from the endothelium and causes subsequent activation of soluble guanylyl cyclase in an active androgen receptor independent manner. This response may contribute to the observed antihypertensive actions of flutamide.     

氧化型低密度脂蛋白对人脐静脉内皮细胞ICAM-1及NO表达的影响

目的研究氧化型低密度脂蛋白(oxidized low density liprotein,ox-LDL)对脐静脉内皮细胞细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM-1)及一氧化氮(nitric oxide,NO)表达的影响.方法采用细胞ELISA法测定细胞表面ICAM-l的含量,硝酸还原酶法测定细胞培养上清液中NO,免疫组化法结合图象分析测定细胞一氧化氮合酶(nitric oxide synthase,NOS)含量.结果 ox-LDL可明显增加脐静脉内皮细胞ICAM-l的表达,并减少NO及NOS的表达,且有浓度依赖性,但无明显的时间依赖性.结论 ox-LDL可损害内皮细胞的功能,减少内皮细胞NO、NOS的表达并增加内皮细胞ICAM-1的表达.这可能为ox-LDL促进动脉粥样硬化的机制之一.     

细胞性一氧化氮供体的建立及其对肿瘤细胞凋亡的诱导效应

目的一氧化氮（ＮＯ）供体细胞系的建立及其对肿瘤细胞凋亡的诱导效应研究。方法采用３Ｈ－胍氨酸转换法进行ＮＯ合成酶（ＮＯＳ）活性测定；亚硝酸盐检测；ＤＮＡ片段的提取及凝胶电泳分析；凋亡细胞的ＤＡＰＩ染色观察；Ｗｅｓｔｅｒｎｂｌｏｔ分析。结果将ｉＮＯＳ真核表达质粒、ｐＣＭＶ／ｉＮＯＳ转染至Ｓｐ２／０骨髓瘤的变异株中，并获得能稳定表达ｉＮＯＳ和合成ＮＯ的重组细胞系（ＳＰｍｔ／ｉＮＯＳ），表达ｉＮＯＳ的效率为每升培养物含４００μｇ蛋白。利用该细胞作ＮＯ细胞性供体，成功地证实ＮＯ能诱导Ｓｐ２／０骨髓瘤细胞发生凋亡。结论所建细胞性ＮＯ供体应用于ＮＯ的生物学功能研究具有ＮＯ合成稳定；更能模拟体内细胞间ＮＯ的信息传递过程；不需任何外源刺激即可合成ＮＯ等独特优点。所建ＮＯ供体细胞可以用于肿瘤细胞凋亡的研究。     

重组卡介苗及猪苓多糖对荷瘤小鼠巨噬细胞NO释放量的影响

目的 观察重组卡介苗（rBCG)和中药猪苓多糖（PPS），对荷瘤小鼠空巨噬细胞释放NO的影响。方法 将黑色素瘤细胞株B16接种于小鼠左大腿外侧皮下，建立荷瘤小鼠模型，分别用rBCG－IL-2,rBCG-IL-2 PPSPPS进行局部治疗。于给药后第1，2，3和5wk处死小鼠，用NO酶法测定小鼠腹腔巨噬细胞释放NO的水平，并观察不同实验组瘤体的变化。结果 rBCG－IL－2组小鼠腹腔巨噬细胞释放NO的水平最高。与对照组相比较，PPS组小鼠腹腔巨噬细胞释放NO的水平在第1wk与第2wk增高，第3wk起与对照组释放的NO水平没有差异。rBCG－IL－2组小鼠随给药时间的延长，皮下瘤体逐渐缩小。PPS组小鼠瘤体在给药后第1wk和第2wk生长缓慢，第3wk起瘤体生长速度明显增加。结论 rBCG－IL－2与PPS能提高小鼠腹腔巨噬细胞释放NO的水平，rBCG－IL－2能明显抑制肿瘤生长。     

Morphine-6beta-glucuronide modulates the expression of inducible nitric oxide synthase

The immunomodulatory effects of morphine are well established; however, suprisingly little is known about the immunomodulatory properties of the major metabolites of morphine. The present study tests the hypothesis that expression of inducible nitric oxide synthase (iNOS) is modulated by the administration of the morphine metabolite, morphine-6-glucuronide. The initial study using rats shows that morphine-6-glucuronide administration (0, 1.0, 3.163, 10 mg/kg s.c.) results in a pronounced reduction in lipopolysaccharide (LPS)-induced expression of iNOS (inducible nitricoxide synthease) in spleen, lung, and liver tissue as measured by western blotting. Morphine-6-glucuronide also produces a reduction in the level of plasma nitrite/nitrate, the more stable end-product of nitric oxide degradation. In a subsequent study, administration of the opioid receptor antagonist, naltrexone (0.1 mg/kg) prior to the injection of morphine-6-glucuronide (10 mg/kg) blocks the morphine-6-glucuronide induced reduction of iNOS expression and plasma nitrite/nitrite levels indicating that the effect is mediated via the opioid-receptor. This study provides the first evidence that morphine-6-glucuronide alters the expression of iNOS.     

Relative significance of the nitric oxide (NO)/cGMP pathway and K+ channel activation in endothelium‐dependent vasodilation in the femoral artery of developing piglets

Mechanisms mediating endothelium‐dependent vasodilation were investigated in femoral artery rings from <2‐day‐old (newborn) and 2‐week‐old piglets. Based on previous results we hypothesized an age difference in the relative contribution of nitric oxide(NO)‐cyclic 3′,5′‐guanosine monophosphate (cGMP) and K⁺ channel‐activation to acetylcholine (ACh)‐induced vasodilation. Changes in vascular tone were studied in organ baths in the absence or presence of NO synthase(NOS) inhibition or K⁺ channel blockade and the intra‐arterial accumulation of cGMP in response to ACh was measured with radioimmunoassay (RIA). In control experiments, relaxant responses to ACh were equal in the two age groups. In the presence of the NOS‐inhibitors N ^G‐monomethyl‐L ‐arginine acetate (L ‐NMMA; 100 μM ) or N^G‐nitro‐L ‐arginine (L ‐NOARG; 1–100 μM ), however, relaxation was significantly more reduced in femoral artery rings from 2‐week‐old than from newborn, with lower pD₂ values in the older age group. Inhibition of large (BK_Ca) conductance calcium‐sensitive K⁺ channels with tetraethylammonium chloride (TEA; 1 mM ), gave a significant rightward shift in the concentration‐response curves to ACh which was of the same magnitude in both age groups. The ACh‐induced vasodilation was abolished in both age groups by high K⁺ (20 mM ) in combination with L ‐NOARG (100 μM ). The relative increase in cGMP levels after addition of ACh (10 nM ) was significantly larger in rings from newborn compared with 2‐week‐old piglets (12‐ vs. four‐fold). In summary, sensitivity to NOS inhibition increased with age while the effect of K⁺ channel blockade with TEA was the same in femoral artery rings from newborn to 2‐week‐old piglets. Lower sensitivity to NOS inhibition and a larger increase in cGMP in response to ACh could indicate a higher efficacy of the NO/cGMP pathway in this vessel in the newborn piglet.     

Xanthii Fructus Inhibits Inflammatory Responses in LPS-Stimulated Mouse Peritoneal Macrophages

Xanthii Fructus (XF) is an herb widely used in medicine for the treatment of a variety of inflammatory pathologies. In this study, using mouse peritoneal macrophages, we have examined whether XF affects nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-12p40 production induced by interferon (IFN)-γ and lipopolysaccharide (LPS). XF inhibits IFN-γ and LPS-induced NO production in a dose dependent manner. The decrease in NO synthesis was reflected as a decreased amount of inducible NO synthase protein. Furthermore, we also found that XF inhibits pro-inflammatory cytokine TNF-α production. However, treatment of XF in peritoneal macrophages had no effect on IL-12p40 production. These findings suggest that XF may be used in controlling macrophages-mediated inflammatory diseases.