Expression of nitric oxide synthase in T-cell-dependent liver injury initiated by ConA in Kunming mice

To investigate whether nitric oxide synthase (NOS) is expressed in T-cell-dependent liver injury initiated by concanavalin A (ConA) in Kunming mice and study the possible effect of nitric oxide(NO) on liver injury models. Methods: Liver injury in Kunming mice was induced by administration of ConA through tail vein. Expression of NOS inthe liver was detected by NADPH diaphorase staining method. The possible effect of NO on liver injury models was obtainedby L-NAME injection to suppress synthesis of NO. Results: NOS has a strong expression in hepatocytes after ConA injection, especially in those close to the central vein, while only a weak expression was found in the epithelial cells in contrml group. Liver injury became more serious when NO symhesis was inhibited by L-NAME, accompanied by great malondlalde-hyde(MDA) increase in serum and severe intrahepatic vascular thrombosis. Conclusion: NOS markedly expressed in ConAinduced liver injury, which may subsequently promote nitric oxide synthesis. Increasement of nitric oxide has a protective ef-fect on ConA-induced liver injury.     

Protective Effect of Propyl Gallate Against Oxidized Low-Density Lipoprotein-Induced Injury of Endothelial Cells

Objective:To evaluate the protective effect of propyl gallate(PG),an alkyl ester of gallic acid which is an active ingredient of Radix Paeoniae,against oxidized low-density lipoprotein(ox-LDL)-induced apoptosis and death in endothelial cells(ECs) and to find out its preliminary mechanism.Methods:The cultured endothelial cells were divided into normal,model(ox-LDL),control(fetal bovine serum),PG high dose(20 μg/mL),PG middle dose(10 μg/mL),and PG low dose(5 μg/mL) groups,each derived from three different pools of umbilical cords.The model of injured human umbilical vein endothelial cells(HUVECs)was induced by ox-LDL.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide(MTT) assay,Hoechst 33258 staining,flow cytometry and measurement of nitrogen monoxidum(NO) release were used to evaluate the protective effect of PG against ox-LDL-induced apoptosis and death in HUVECs.To find out the mechanism of this protective effect,the expression of endothelial nitric oxide synthase(eNOS) mRNA,eNOS protein expression,immunofluorescence of intracellular reactive oxygen species(ROS) and activities of malondialdehyde(MDA),superoxidedismutase(SOD) and glutathione peroxidase(GPx) were observed.Results:PG significantly reduced ox-LDL-induced apoptosis and cell death.The percentage of cells death and apoptosis was significantly higher in the ox-LDL group than that in the control group(P0.05).Compared with the control group,the cells death and apoptosis of PG group was no different(P0.05).As compared with the ox-LDL group,results of the PG high dose group showed that cell viability was significantly increased(P0.05),the level of NO release,expression of eNOS mRNA,densitometric value of eNOS protein expression,as well as the activities of SOD and GPx were all significantly higher(all P0.05).Conclusion:PG could potentially serve as a novel endothelial protective agent against ox-LDL-induced injury of endothelial cell.     

Aqueous Extracts of Tribulus terrestris Protects Against Oxidized Low-Density Lipoprotein-Induced Endothelial Dysfunction

Objective:To investigate the role of aqueous extracts of Tribulus terrestris(TT) against oxidized low-density lipoprotein(ox-LDL)-induced human umbilical vein endothelial cells(HUVECs) dysfunction in vitro.Methods:HUVECs were pre-incubated for 60 min with TT(30 and 3 μg/mL respectively) or 10~(-5) mol/L valsartan(as positive controls) and then the injured endothelium model was established by applying 100 μg/mL ox-LDL for 24 h.Cell viability of HUVECs was observed by real-time cell electronic sensing assay and apoptosis rate by Annexin V/PI staining.The cell migration assay was performed with a transwell insert system.Cytoskeleton remodeling was observed by immunofluorescence assay.The content of endothelial nitric oxide synthase(eNOS) was measured by enzyme-linked immunosorbent assay.Intracellular reactive oxygen species(ROS) generation was assessed by immunofluorescence and flow cytometer.Key genes associated with the metabolism of ox-LDL were chosen for quantitative real-time polymerase chain reaction to explore the possible mechanism of TT against oxidized LDL-induced endothelial dysfunction.Results:TT suppressed ox-LDL-induced HUVEC proliferation and apoptosis rates significantly(41.1%and 43.5%after treatment for 3 and 38 h,respectively;P0.05).It also prolonged the HUVEC survival time and postponed the cell's decaying stage(from the 69 th h to over 100 h).According to the immunofluorescence and transwell insert system assay,TT improved the endothelial cytoskeletal network,and vinculin expression and increased cell migration.Additionally,TT regulated of the synthesis of endothelial nitric oxide synthase and generation of intracellular reactive oxygen species(P0.05).Both 30 and 3 μg/mL TT demonstrated similar efficacy to valsartan.TT normalized the increased mRNA expression of PI3Kα and Socs3.It also decreased mRNA expression of Akt1,AMPKα1,JAK2,LepR and STAT3 induced by ox-LDL.The most notable changes were JAK2,LepR,PI3 K α,Socs3 and STAT3.Conclusions:TT demonstrated potential lowering lipid benefits,anti-hypertension and endothelial protective effects.It also suggested that the JAK2/STAT3 and/or PI3K/AKT pathway might be a very important pathway which was involved in the pharmacological mechanism of TT as the vascular protective agent.     

Vascular endothelial growth factor up-regulates the expression of intracellular adhesion molecule-1 in retinal endothelial cells via reactive oxygen species, but not nitric oxide

Background The vascular endothelial growth factor （VEGF） is involved in the initiation of retinal vascular leakage and nonperfusion in diabetes. The intracellular adhesion molecule-1 （ICAM-1） is the key mediator of the effect of VEGFs on retinal leukostasis. Although the VEGF is expressed in an early-stage diabetic retina, whether it directly up-regulates ICAM-1 in retinal endothelial cells （ECs） is unknown. In this study, we provided a new mechanism to explain that VEGF does up-regulate the expression of ICAM-1 in retinal ECs. Methods Bovine retinal ECs （BRECs） were isolated and cultured. Immunohistochemical staining was performed to identify BRECs. The cultured cells were divided into corresponding groups. Then, VEGF （100 ng/ml） and other inhibitors were used to treat the cells. Cell lysate and the cultured supernatant were collected, and then, the protein level of ICAM-1 and phosphorylation of the endothelial nitric oxide synthase （eNOS） were detected using Western blotting. Griess reaction was used to detect nitric oxide （NO）. Results Western blotting showed that the VEGF up-regulated the expression of ICAM-1 protein and increased phosphorylation of the eNOS in retinal ECs. Neither the block of NO nor protein kinase C （PKC） altered the expression of ICAM-1 or the phosphorylation of eNOS. The result of the Western blotting also showed that inhibition of phosphatidylinositol 3-kinase （PI3K） or reactive oxygen species （ROS） significantly reduced the expression of ICAM-1. Inhibition of PI3K also reduced phosphorylation of eNOS. Griess reaction showed that VEGF significantly increased during NO production. When eNOS was blocked by L-NAME or PI3K was blocked by LY294002, the basal level of NO production and the increment of NO caused by VEGF could be significantly decreased. Conclusion ROS-NO coupling in the retinal endothelium may be a new mechanism that could help to explain why VEGF induces ICAM-1 expression and the resulting leukostasis in diabetic retinopathy.     

Endothelial nitric oxide synthase traffic inducer in the umbilical vessels of the patients with pre-eclampsia

The expression of endothelial nitric oxide synthase traffic inducer （NOSTRIN） was examined in the umbilical vessels of the patients with pre-eclampsia （PE） to explore its possible role in the pathogenesis of PE. The NOSTR1N rnRNA in umbilical tissues was determined by RT-PCR. The eNOS activity in umbilical vessels was spectrophotometrically detected. NO2 /NO3, the stable metabolic end products of NO, was measured by using nitrate reductase. RT-PCR showed that the expression level of NOSTRIN was significantly higher in women with PE than in the normal group （P〈0.01）. The activity of eNOS was significantly decreased in PE group [（12.83±3.61） U/mg] than in normal group [（21.72±3.83） U/mg] （P〈0.01）. The level of NO2-/NO3- in PE patients （27.53±7.48） pmol/mg was significantly lower than that of normal group （54.27±9.53） μmol/mg （P〈0.01）. The significant negative correlation existed between the expression of NOSTRIN and the activity of eNOS in umbilical vessels of women with PE （r=-0.58, P〈0.01）. It was concluded that the level of NOSTR1N expression was increased in umbilical vessel of women with PE, indicating that it may be involved in the pathogenesis of PE.     

Ginsenoside Rgl-induced alterations in gene expression in TNF-α stimulated endothelial cells

Background In China the ginseng root began to be used in medicine over 2000 years ago.Ginsenosides are the most important component isolated from ginseng. The authors investigated the effect of ginsenoside Rgl on the spectrum of gene expression in the endothelial cells stimulated by TNF-α and further explored the potential molecular mechanism of endothelial protection by ginsenoside Rgl.Methods Nitric oxide (NO) production in(HUVECs) was measured by using an NOthe cultured human umbilical vein endothelial cells assay kit. A home-made oligonucleotide microarray containing approximately 400 cardiovascular disease-related genes was constructed. The alteration of the spectrum of gene expression induced by ginsenoside Rgl in HUVECs which were activated by TNF-α were detected by oligonucleotide microarray analysis.Results NO production in HUVECs was decreased significantly after TNF-α treatment, while pretreatment with ginsenoside Rgl enhanced NO production in TNF-αstimulated HUVECs.Ginsenoside Rg1 affected the expression levels of genes involved in vascular constriction, cell adherence, coagulation, cell growth and signal transduction in TNF-αstimulated HUVECs.Conclusions Ginsenoside Rgl could enhance NO production and the expression of eNOS mRNA in TNF-α stimulated HUVECs. Ginsenoside Rgl regulated sets of genes in endothelial cells and protected endothelial cells from TNF-αectivation. Microarray analysis provided us with valuable insights into the atheroprotective mechanism by gingsenoside Rg1.     

Tetrandrine Ameliorates Cirrhosis and Portal Hypertension by Inhibiting Nitric Oxide in Cirrhotic Rats

To examine the role and effect of nitric oxide synthase type Ⅱ (NOSⅡ) in cirrhotic rats, expression of NOSⅡ mRNA was detected by real time RT-PCR. The enzymatic activity of nitric oxide synthase and the circulating levels of NO, systemic and portal hemodynamics and quantification of cirrhosis were measured. Chinese traditional medicine was used to treat cirrhotic rats and. the effect of NO was evaluated. Double-blind method was used in experiment. Our results showed the concentration of NO and the enzymatic activity, of NOS increased markedly at all stages of cirrhosis and iNOSmRNA was strongly expressed. Meanwhile, the portal-venous-pressure (PVP) and portal-venous-flow (PVF) were significantly increased. NO, NOS and iNOSmRNA were positively correlated to the degree of hepatic fibrosis. Tetrandrine significantly inhibited NO production and the expression of iNOSmRNA. Our results suggested that increased hepatic expression of NOSⅡ isone of the important factors causing cirrhos is and portal hypertension. Tetrandrine can significantly ameliorate cirrhosis and portal hypertension.     

Effects of Nephritis No.3 Recipe on Nitric Oxide,Nitric Oxide Synthase Secreted by Cultured Mesangial Cells in Rats and the Gene Expression of Inducible Nitric Oxide Synthase

Objective:To explore the effect of the Nephritis No.3(N-3)recipe on nitric oxide(NO),nitric oxide synthase(NOS)secreted by cultured mesangial cells(MC)and its gene expression of the in-ducible nitric oxide synthase(iNOS).Methods:The drug(nephritis No.3)-containing serum was preparedwith serum pharmacological technique,and then was applied to react on mesangial cells cultured In fetalcalf serum(FCS)and cells cultured in FCS plus lipopolysaccharide.To observe the secretion of NO andNOS and the gene expression of iNOS by means of RT-PCR.Results:Under the two kinds of culture con-ditions,the content of NO and NOS in the groups with drug-containing serum were higher than thosewithout drug-containing serum(P<0.05,P<0.01),and the expression of iNOS mRNA was up-regula-ted too.Conclusion:The N-3 could significantly promote the secretion of NO and NOS and the mRNA ex-pression of iNOS in rats.     

Changes in human umbilical vein endothelial cells induced by endothelial nitric oxide synthase traffic inducer

This study investigated the changes in human umbilical vein endothelial cells (HUVECs) induced by overexpression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) and its role in cellular injury. Recombinant NOSTRIN-expressing and empty vectors were transfected into cultured HUVECs, and factor Ⅷ-related antigen was examined by using immunohistochemical analysis. Growth curves were generated for both transfected and untransfected cells and these indicated that the proliferative ability of cells overexpressing NOSTRIN was significantly decreased. The expression of NOSTRIN and eNOS proteins was detected by using Western blot analysis, endothelial NOS (eNOS) activity was assayed by using spectrophotometry, and NO 2 /NO 3 levels were measured using nitrate reductase. Immunohistochemical analysis demonstrated that all groups expressed NOSTRIN in the plasma membrane and cytoplasm, and Western blot analysis confirmed that NOSTRIN levels were significantly higher in cells transfected with the NOSTRIN plasmid (P<0.01). The activity of eNOS and the levels of NO 2 /NO 3 were significantly decreased in NOSTRIN overexpressing cells as compared with empty vector and untransfected cells (P<0.01 and P<0.01, respectively). Morphological and ultrastructural changes were observed under light and electron microscopy, and it was found that NOSTRIN-overexpressing cells were elongated with deformities of the karyotheca, injury to the plasma membrane, increased lipids in the cytoplasm, and shortened microvilli. This study showed that overexpression of NOSTRIN had a significant effect on eNOS activity in HUVECs and resulted in significant cellular damage.     

福辛普利与缬沙坦对氧化型低密度脂蛋白诱导的人脐静脉内皮细胞ICAM-1及NO表达的影响

目的 研究福辛普利与缬沙坦对氧化性低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)诱导的脐静脉内皮细胞细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM1-)及一氧化氮(nitric oxide,NO)表达的影响.方法 采用硝酸还原酶法测定细胞培养液上清中 NO 的含量,细胞 ELISA 法测定细胞表面 ICAM-1 的含量,免疫组织化学法结合图像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各时点 ICAM-1 的表达,并减少 NO 及 NOS 的表达,且有浓度依赖性.福辛普利与缬沙坦均可显著抑制 ox-LDL 的上述作用,两者作用的差异无显著性意义.结论 抑制 ox-LDL 诱导的内皮细胞 ICAM-1 的表达,并增加内皮细胞 NO的合成,可能为福辛普利与缬沙坦抗动脉粥样硬化的作用机制之一.     

脱氢表雄酮对血管内皮细胞损伤后单核细胞与内皮细胞相互作用的影响

目的脱氢表雄酮(dehydroepiandrosterone,DHEA)是成人体内最为丰富的来源于肾上腺的甾体激素,文中探讨DHEA对氧化型低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)所致血管内皮细胞损伤后单核细胞与内皮细胞相互作用的影响。方法以培养的人脐静脉内皮细胞(human umbilical vein endothelial cell,HUVEC)作为靶细胞,在内皮细胞培养基中加入ox-LDL或在试验体系中加入不同浓度的DHEA,测定人单核细胞系U937与HUVEC的黏附,检测内皮细胞条件培养基中一氧化氮(nitric oxide,NO)及单个核细胞趋化蛋白-1(monocyte chemoattractant protein,MCP-1)的含量,应用流式细胞仪检测内皮细胞表面黏附分子细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM-1)、血管细胞黏附分子-1(vascularcell adhesion molecule-1,VCAM-1)及E-选择素的表达。将内皮细胞条件培养基作用于U937细胞,应用RT-PCR检测U937细胞CCR2、LFA-1以及VLA-4 mRNA的表达。结果 DHEA可明显抑制单核U937细胞与内皮细胞之间的相互黏附,明显促进内皮细胞NO合成,抑制MCP-1分泌,降低内皮细胞表面ICAM-1、VCAM-1的表达,且经DHEA作用后的内皮细胞条件培养基可明显抑制单核U937细胞CCR2、淋巴细胞功能相关抗原(lymphocyte function-associated antigen,LFA)-1以及非常晚期抗原(very late antigen,VLA)-4 mRNA的表达。结论 DHEA可通过抑制内皮细胞分泌趋化因子、下调内皮细胞表面黏附分子的表达,抑制内皮细胞对单核细胞的趋化及相互黏附,据此认为DHEA可能对血管内皮细胞具有保护作用。     

Cinaciguat对高糖损伤血管内皮细胞功能的影响

目的 糖尿病状态下，一氧化氮(NO)与可溶性鸟苷酸环化酶(soluble guanylatecyclase,sGC)均被氧化，使NO-sGC-环磷酸鸟苷(cGMP)信号通路传导异常，NO-sGC-cGMP信号通路异常是糖尿病血管内皮功能障碍的重要病理基础。可溶性鸟苷酸环化酶激活剂(cinaciguat，CIN)可激活失活的sGC进而起到保护血管内皮细胞功能的作用。本研究通过体外实验制造高糖内皮细胞损伤模型，观察CIN对人脐静脉内皮细胞功能的影响。 方法 培养人脐静脉内皮细胞，并将细胞分为正常对照组、高糖组、CIN干预组，每组6例。高糖组及CIN干预组均加入33.3 mmol/L的葡萄糖制造高糖细胞损伤模型，而CIN组同时加入0.1 μmol/L CIN干预。各组细胞在培养6、24、48 h时，检测上清液中的NO水平及细胞内一氧化氮合酶(NOS)浓度；培养48 h后RT-PCR检测细胞内诱导型一氧化氮合酶(iNOS)、内皮型一氧化氮合酶(eNOS)mRNA的表达；培养48 h后Western blotting检测细胞间粘附分子-1(ICAM-1)及血管粘附分子-1(VCAM-1)蛋白的表达。 结果 与正常对照组相比，高糖组NO、NOS含量呈现早期升高晚期下降的趋势，而CIN组上述趋势消失；与正常组比较，高糖组内皮细胞的eNOS mRNA表达水平降低(P＜0.05)，iNOS mRNA、ICAM-1与VCAM-1蛋白表达明显升高(P＜0.05)，而CIN组eNOS mRNA表达水平较高糖组明显升高(P＜0.05)，iNOS、ICAM-1与VCAM-1蛋白的表达水平明显降低(P＜0.05)。 结论 CIN可平衡NOS的活性，调节NO的生成及ICAM-1与VCAM-1的表达，改善高糖状态下内皮细胞的功能。      

活血注射液对ox-LDL诱导的单核-内皮细胞黏附作用的影响

目的观察活血注射液对氧化低密度脂蛋白(ox-LDL)诱导的人脐静脉内皮细胞(HUVEC)中细胞间黏附分子-1(ICAM-1)的表达及与人单核细胞黏附作用的影响。方法以培养HUVEC作为靶细胞,在内皮细胞培养基中加入ox-LDL制备细胞损伤模型。采用蛋白定量法检测HUVEC与单核细胞的黏附率;RT-PCR检测HUVEC中ICAM-1的mRNA表达;用流式细胞仪测定HUVEC中ICAM-1的蛋白表达。结果ox-LDL作用HUVEC后12、24h时,人单核细胞与HUVEC的黏附率显著升高,HUVEC中ICAM-1的mRNA和蛋白表达水平也均明显升高,均明显高于正常对照组(P<0.01),而活血注射液可明显降低人单核细胞与HUVEC的黏附率,以及显著降低ICAM-1的mRNA和蛋白的表达水平(P<0.05,P<0.01),这种作用随着剂量的增加而增强。结论活血注射液能通过下调内皮细胞表面黏附分子的表达抑制单核-血管内皮细胞黏附,从而发挥对血管内皮细胞的保护作用,有利于减少或抑制动脉粥样硬化的形成。     

大黄素对内皮细胞一氧化氮合成的影响

目的观察大黄素对内皮细胞一氧化氮及一氧化氮合酶合成的影响。方法通过选用新生儿脐静脉,采用灌注消化法建立内皮细胞模型,分别取10．0mg／L、37．5mg／L、75．0mg／L大黄素作用于细胞模型,测定细胞培养液中NO、NOS含量。结果大黄素在75．0mg/L浓度时NO、NOS合成明显增加,与对照组比较差异有统计学意义（P〈0．05）,且其合成是脉冲式的。结论大黄素可以通过调控NOS的合成,促进NO的生成,对内皮细胞具有促进其功能的作用。     

ox-LDL对PLGF作用内皮细胞释放NO和内皮细胞黏附分子的影响

目的：探讨氧化型低密度脂蛋白对胎盘生长因子-1作用人脐静脉内皮细胞释放一氧化氮和内皮细胞黏附分子的影响。方法：在ox-LDL（25μg／mL）条件下,应用不同浓度的PLGF-1（20、40、80ng／mL）孵育ECV-304,对照组为内皮细胞未受损时,相同浓度梯度的PLGF-1孵育ECV-304,3h、6h、12h、24h后应用ELISA法检测内皮细胞黏附分子-可溶性细胞间黏附因子-1、可溶性血管内皮细胞黏附因子-1的表达,硝酸盐还原酶法检测NO的表达。结果：正常生理条件下,PLGF诱导NO和内皮细胞黏附分子的表达,且呈时间（当t=6h达到最理想的分泌量）、浓度依赖关系。在氧化损伤条件下,PLGF诱导NO的表达下降,而内皮细胞黏附分子的表达则增高,以VCAM-1表达增多更为明显。结论：氧化损伤是动脉粥样硬化的独立危险因素,而PLGF诱导内皮的活化,上调内皮黏附分子的表达,可进一步促使疾病的恶化。故认为抑制PLGF的生物活性可达到控制炎症反应的作用。     

精氨酸类似物对一氧化氮合酶的影响

目的 研究新精氨酸类似物对一氧化氮及诱导型一氧化氮合酶（iNOS）的影响。方法 脂多糖刺激巨噬细胞，检测不同浓度新精氨酸类似物对诱导型iNOS的抑制程度；胰岛素刺激脐静脉内皮细胞，检测新精氨酸类似物对于内皮细胞的iNOS的抑制作用。结果 （1）新精氨酸类似物可显著抑制脂多糖刺激的巨噬细胞产生一氧化氮，并呈剂量依赖性。而对胰岛素刺激的内皮细胞一氧化氮产生无明显影响。（2）新精氨酸类似物可显著降低巨噬细胞iNOS的活性，对于巨噬细胞的结构型iNOS活性及内皮细胞的iNOS活性无明显影响。（3）新精氨酸类似物对于巨噬细胞iNOS的蛋白表达无明显影响。结论 新精氨酸类似物是一种具有高度选择性的iNOS抑制剂。     

胰岛素样生长因子-1对高胆固醇血症患者内皮的保护作用及机制

目的:探讨血清胰岛素样生长因子-1 (insulin-like growth factor-1, IGF-1) 对高胆固醇血症血管内皮的保护作用及机制。方法:观察高胆固醇血症患者和正常对照( 各25 例) 肱动脉血流介导的血管舒张功能(flow-mediatedarterial diastolic function, FMD), 并检测血清中IGF-1、非对称二甲基精氨酸(asymmetric dimethylarginine, ADMA)、一氧化氮合酶(nitric oxide synthase, NOS) 以及一氧化氮(NO) 水平;将培养的人脐静脉内皮细胞分为3 组:正常对照组、氧化型低密度脂蛋白(oxidized low-density lipoprotein, ox-LDL) 损伤组和IGF-1 干预组, 培养24 h 后, 检测各组细胞培养液中ADMA, NOS, NO 水平, 细胞裂解液中二甲基精氨酸二甲胺水解酶(dimethylarginine dimethylamine hydrolase, DDAH) 活性, 并进行β- 半乳糖苷酶染色, 计算细胞衰老率。结果:临床实验中, 高胆固醇血症患者FMD 显著下降;伴随血清IGF-1, NOS 以及NO 水平的下降, ADMA 水平升高。多元线性回归分析显示IGF-1 与FMD 呈正相关, ADMA 与FMD 呈负相关。细胞实验中, ox-LDL 处理24 h 后, 细胞裂解液DDAH 活性下降;伴随上清液中ADMA 水平升高, NOS 和NO 水平下降和细胞衰老率增加, 给予IGF-1 干预能部分逆转上述作用。结论:血液中IGF-1 水平下降可能是高胆固醇血症患者血管内皮舒张功能受损的重要原因之一;IGF-1 具有抗内皮细胞衰老作用, 其机制可能涉及对DDAH/ADMA 途径的调节。     

茶多酚对高糖时内皮细胞产生NO、NOS和ICAM-1的影响

目的:研究在高糖环境下人脐静脉内皮细胞(ECV304)产生一氧化氮(NO)量及其合酶和表达细胞间黏附分子1(intercellular adhesion molecule 1,ICAM鄄1)的变化,以及茶多酚(tea polyphenols,TPs)的干预作用。方法:培养ECV304,加入不同培养液,分为正常对照组、高糖组、茶多酚组、茶多酚干预组,以硝酸还原酶法测定培养液中NO的代谢产物NO2/NO3鄄(NOX-)含量,用分光光度法检测培养液中NOS活性,用逆转录鄄多聚酶链反应(RT鄄PCR)和细胞酶联免疫吸附法(ELISA)观察ICAM鄄1的基因和细胞表面蛋白的表达。结果:高糖组NO含量、NOS活性、ICAM鄄1的基因和蛋白表达较正常对照组显著增加,且ICAM鄄1的蛋白表达呈现一定的时间依赖性;茶多酚干预组显著抑制高糖时NO含量、NOS活性以及ICAM鄄1的基因和蛋白表达的上调。结论:高糖时内皮细胞NOS的激活、NO的大量释放以及ICAM鄄1mRNA和蛋白的表达上调,对糖尿病早期进展起一定作用,茶多酚对这种损伤具有明显的保护作用。     

北极刺参多糖、皂苷和胶原蛋白多肽对血管内皮细胞的保护作用

目的:研究北极刺参多糖、皂苷和胶原蛋白多肽对血管内皮细胞的保护作用。方法:采用氧化型低密度脂蛋白(ox-LDL)建立体外培养的人脐静脉血管内皮细胞株(ECV304)损伤模型。MTT法测定血管内皮细胞的增殖活性,硝酸还原酶法测定血管内皮细胞一氧化氮合酶(NOS)活力和NO释放量,TBA法测定细胞内丙二醛(MDA)含量,DNA-Ladder法检测血管内皮细胞的凋亡。结果:不同浓度的北极刺参多糖和胶原蛋白多肽均能显著抑制ox-LDL对血管内皮细胞的氧化损伤,促进血管内皮细胞增殖(P<0.05,P<0.01),降低细胞内MDA含量(P<0.05,P<0.01),促进血管内皮细胞NO释放量(P<0.05,P<0.01),提高细胞NOS活力(P<0.05,P<0.01),拮抗ox-LDL引起的血管内皮细胞凋亡。刺参皂苷具有显著的细胞毒性作用,仅能降低ox-LDL氧化损伤细胞内MDA含量(P<0.05,P<0.01),而无其他上述作用。结论:北极刺参多糖和胶原蛋白多肽对血管内皮细胞的脂质过氧化物损伤均具有显著的保护作用。