Urantide对缺血/再灌注损伤诱导的心肌细胞凋亡的影响(英文)

目的探讨urantide对大鼠心肌缺血/再灌注(I/R)或缺氧/复氧损伤(H/R)诱导的心肌细胞凋亡的影响及其相关机制。方法①在体实验采用冠状动脉左前降支缺血30 min/灌注60 min法建立大鼠在体心肌I/R模型。Urantide 3,10和30μg.kg-1分别于缺血前10 min经舌下静脉给药。TUNEL法检测心肌细胞凋亡,免疫组织化学方法检测心肌细胞内Bcl-2和Bax蛋白的表达水平。②离体实验乳大鼠心肌细胞行缺氧3 h/复氧3 h处理制备H/R模型。Urantide 0.1,1和10 nmol.L-1分别于缺氧前加入。Ho-echst33258染色和流式细胞术检测心肌细胞凋亡。结果①在体实验与假手术组相比,I/R组TUNEL阳性细胞数量明显升高(P<0.01);Bcl-2蛋白表达量轻度升高,但无统计学差异,Bax蛋白表达量显著升高(P<0.01),Bcl-2/Bax比值明显降低(P<0.01)。与I/R组相比,urantide 10,30μg.kg-1组心肌凋亡细胞显著降低,分别较模型组降低36.6%和57.2%(P<0.05);Bax蛋白表达量显著降低(P<0.05),Bcl-2/Bax比值明显升高(P<0.05);同时,urantide 30μg.kg-1组Bcl-2蛋白表达量也明显升高(P<0.05)。②离体实验与正常对照组相比,H/R组细胞凋亡率明显升高(P<0.01);Hoechst33258结果显示,与模型组相比,uran-tide 0.1,1和10 nmol.L-1组细胞凋亡率分别显著降低了27.9%,59.0%和75.4%(P<0.05)。流式细胞术结果显示,urantide 1和10 nmol.L-1组细胞凋亡率显著降低,分别较H/R模型组降低32.8%和64.7%(P<0.01)。结论 Urantide可减轻I/R或H/R损伤诱导的心肌细胞凋亡,其机制可能与增加Bcl-2蛋白表达,降低Bax蛋白表达有关。     

urantide抑制动脉粥样硬化大鼠单核细胞趋化蛋白-1的表达

目的研究urantide对动脉粥样硬化(AS)大鼠胸主动脉及血管平滑肌细胞(VSMC)中单核细胞趋化蛋白-1(MCP-1)的表达的影响。方法 (1)在体实验:采用给予高脂饮食及ip给予维生素D3制备AS模型。AS大鼠分别尾静脉注射urantide 30μg.kg-1.d-1,分为3,7和14 d组。于各实验结束时间点测量体质量,检测血中甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)和Ca2+;免疫组化法检测胸主动脉中MCP-1表达。(2)体外实验:贴块法制备的血管平滑肌细胞(VSMC)中加入尾加压素Ⅱ(UⅡ)10μmol.L-1+urantide 0.1,1,10 nmol.L-1,0.1和1μmol.L-1作用48 h,ELISA法检测细胞中MCP-1含量。结果 (1)在体实验:与AS模型组比较,只有14 d urantide给药组的体质量显著增加(P<0.05);3 d组、7 d组及14 d组血清中Ca2+,TG,TC,HDL及LDL均随给药时间的延长呈现逐渐降低的趋势(P<0.01),达到或接近阳性药氟伐他汀组水平;在大鼠胸主动脉内膜及中膜斑块内,与AS模型对照组相比,urantide 3 d组、7 d组及14 d组MCP-1阳性染色强度和范围均减少。(2)体外实验:urantide各浓度组对VSMC培养上清中MCP-1的表达均有下调趋势(P<0.05)。结论 urantide在大鼠动脉粥样硬化中可抑制炎症因子MCP-1的表达。     

Urantide对急性肝衰竭小鼠肝组织p120⁃catenin表达的影响

目的：探讨尾加压素Ⅱ（urotensinⅡ,UⅡ）受体拮抗剂urantide对急性肝衰竭（acute liver failure,ALF）小鼠肝组织p120?catenin（p120ctn）表达的影响。方法：24只雄性Balb/c小鼠随机分为健康对照组、预处理对照组、ALF模型组和预处理ALF组（6只/组）。ALF模型组和预处理ALF组均以脂多糖（lipopolysaccharide,LPS）50 μg/kg联合D?半乳糖胺（D?galactosamin,D?GalN）800 mg/kg腹腔注射诱导ALF,健康对照组注射等体积的0.9%氯化钠溶液;预处理ALF组在造模前30 min给予0.6 mg/kg urantide尾静脉注射;预处理对照组经同样预处理后腹腔注射等体积的0.9%氯化钠溶液。造模12 h后,采集动物肝组织标本。肝组织p120ctn mRNA和蛋白质表达分别采用实时荧光定量PCR（real?time PCR）和免疫印迹（Western blot）分析方法检测。结果：p120ctn mRNA和蛋白相对表达水平在健康对照组和预处理对照组之间差异无统计学意义;而健康对照组、预处理对照组和预处理ALF组p120ctn mRNA和蛋白相对表达水平均显著高于ALF模型组（P < 0.05）。结论：LPS/D?GalN诱导ALF小鼠肝内p120ctn表达受抑可能与UⅡ/UT信号系统的激活有关。     

Opposite actions of urotensin II and relaxin‐2 on cellular expression of fibronectin in renal fibrosis: A preliminary experimental study

Our aim was to evaluate the role of urotensin II, urantide (urotensin II receptor antagonist) and relaxin‐2 on the cellular expression of fibronectin as a surrogate marker for renal fibrosis. We employed LLC‐PK1 renal tubular epithelial cells and assessed the influence on the fibrotic process of the above‐mentioned substances by using anti‐fibronectin antibodies in western blot analysis. The addition of urotensin II increased fibronectin expression. Urantide reduced the positivity for fibronectin caused by urotensin II (P<.05). The anti‐fibrotic action was more evident for relaxin‐2 (P<.01). Also in the model of TGF‐β1‐induced fibrosis, urantide and, to a greater extent, relaxin‐2 were able to significantly lessen fibronectin expression (respectively, P<.05 and P<.01). In conclusion, relaxin‐2 may reduce urotensin II‐induced renal fibrosis.     

urantide对动脉粥样硬化大鼠血钙、血脂和心肌酶学指标的影响

目的：探讨urantide对动脉粥样硬化（AS）大鼠血钙、血脂和心肌酶学指标的影响,阐明其防治AS的作用机制。方法：选取180只Wistar大鼠,随机分为正常对照组、AS组、阳性药（辛伐他汀）组和urantide组（3、7和14 d组）,每组30只。采用腹腔注射维生素D₃（VD₃）和高脂饲料喂养的方法建立大鼠AS模型。各组大鼠在实验前、用药前和实验结束时分别称体质量,并应用全自动生化分析仪检测各组大鼠血清中Ca²⁺、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）、肌酸激酶（CK）和乳酸脱氢酶（LDH）水平。结果：正常对照组大鼠体质量随着饲养时间的延长而增加;与正常对照组比较,AS组大鼠用药前体质量明显降低（P<0.01）;与AS组比较,各给药组大鼠给药后体质量不同程度增加（P<0.05或P<0.01）。与正常对照组比较,AS组大鼠血清中Ca²⁺、TC、TG、LDL、CK和LDH水平均明显升高（P<0.01）,而HDL水平则明显降低（P<0.01）;与AS组比较,urantide组大鼠血清中Ca²⁺、TC、TG、LDL、CK和LDH水平均明显降低（P<0.05或P<0.01）,而HDL水平升高（P<0.05或P<0.01）。结论：urantide可通过下调或上调AS大鼠血清中Ca²⁺、血脂和心肌酶学指标水平而起到防治AS的作用。     

The effects of urotensin II and urantide on forearm blood flow and systemic haemodynamics in humans

AIMS

(i) To compare the effects of intra-arterial administration of urotensin II in patients with CVD with healthy volunteers, and (ii) to study the haemodynamic effects of intra-arterial infusion of the urotensin II receptor antagonist, urantide.

METHODS

Ten healthy volunteers and 10 patients with CVD received a dose-ramped brachial artery infusion of urotensin II. A further six healthy male volunteers received a prolonged urotensin II infusion and 11 healthy male volunteers received a dose-ramped infusion of urantide. Forearm blood flow (FBF) was measured every 20 min and blood pressure and heart rate were assessed every 20 min.

RESULTS

In healthy volunteers and patients with CVD, intra-arterial infusion of urotensin II had no effect on FBF ratio. A dose-ramped infusion of urantide similarly had no effect on FBF ratio. During dose-ramped infusions of urotensin II and urantide, systolic and mean arterial blood pressure increased significantly. In healthy volunteers, urotensin II and urantide, respectively, increased systolic blood pressure from 133 ± 6 to 137 ± 5 mmHg (P < 0.01) and from 113 ± 4 to 120 ± 4 mmHg (P < 0.01). In patients with CVD, heart rate also significantly increased during dose-ramped infusion of urotensin II from 59 ± 3 to 62 ± 4 bpm (P < 0.05).

CONCLUSIONS

We have shown no in vivo effect of urotensin II or urantide on human forearm resistance vessels. Previous discrepancies do not seem to relate to either the age or CVD status of subjects. Changes in systemic cardiovascular haemodynamics during the dose-ramped infusion studies are unlikely to be caused by urotensin II receptor modulation.     

Urantide对心肌缺血性损伤的保护作用

研究UT受体拮抗剂——urantide对心肌缺血性损伤的保护作用及其机制。小鼠心肌缺血采用皮下注射(sc)异丙肾上腺素(Iso)法，观察心电图ST段的变化，测定小鼠血清中乳酸脱氢酶(LDH)、一氧化氮合酶(NOS)的活性以及丙二醛(MDA)、一氧化氮(NO)的含量， HE染色观察心肌组织病理损伤情况。建立乳鼠原代心肌细胞缺氧再给氧模型，采用ELISA法观察urantide对细胞培养上清液中肌钙蛋白I(cTnI)的影响，比色法测LDH活性；MTT法观察细胞存活率及激光共聚焦检测细胞内钙离子浓度的变化。实验揭示urantide (3～30 μg·kg^-1)可明显抑制小鼠心电图ST段的抬高； urantide (10及30 μg·kg^-1)可显著降低小鼠血清中LDH活性和MDA含量，明显升高NOS活性和NO含量，同时减轻异丙肾上腺素诱导的心肌病理损伤。在乳鼠原代心肌细胞缺氧再给氧模型中， urantide (1×10^-6和1×10^-7 mol·L^-1)能明显增加细胞存活率，降低培养上清液中LDH的活性； urantide (1×10^-6～1×10^-9 mol·L^-1)能显著降低细胞培养上清液中cTnI的增高和细胞内钙离子浓度的上升。上述结果表明， urantide对心肌缺血及缺氧再给氧所致心肌细胞的损伤具有一定的保护作用，其作用机制可能与增加NOS活性、促进NO合成及抑制钙超载有关。     

Urotensin-II receptor antagonism does not improve renal haemodynamics or function in rats with endotoxin-induced acute kidney injury

1. Urotensin-II (U-II) is a vasoactive peptide that influences renal haemodynamics and kidney function. The aim of the present study was to examine the effects of the selective U-II receptor antagonist, urantide, on renal haemodynamics, oxygenation and function in endotoxaemic rats. 2. Endotoxaemia was induced in Sprague-Dawley rats by an intraperitoneal dose of lipopolysaccharide (LPS; Escherichia coli O127:B8, 7.5 mg/kg). At 16 h after endotoxin was given, renal clearance experiments were carried out in thiobutabarbital anaesthetized rats. Group 1, sham-saline; group 2, sham-urantide; group 3 LPS-saline; and group 4, LPS-urantide received isotonic saline or urantide (0.2 mg/kg bolus intravenously, followed by an infusion of 1.2 mg/kg/h throughout) after baseline measurements. Kidney function, renal blood flow (RBF), and cortical and outer medullary perfusion (laser-Doppler flowmetry) and oxygen tension (Clark-type microelectrodes) were analysed during 2 h of drug administration. 3. At baseline, endotoxaemic rats showed approximately 50% reductions in glomerular filtration rate (GFR) and RBF (P < 0.05), a decline in cortical and outer medullary perfusion and pO(2) (P < 0.05), and a significant increase in mean arterial pressure (MAP; P < 0.05) compared with saline-injected controls. In sham animals, urantide in a dose that did not significantly influence MAP or RBF, increased GFR (P < 0.05 time × treatment interaction) and filtration fraction (P < 0.05 treatment effect). However, urantide had no statistically significant effects on any of the investigated variables in endotoxaemic rats. 4. These findings show that U-II, through the UT receptor, does not contribute to abnormalities in renal haemodynamics and function in endotoxaemic rats.     

Urantide对心肌缺血/再灌注损伤的保护作用

目的研究UT受体(urotensinⅡreceptor,UTS2R)拮抗剂——urantide对心肌缺血/再灌注(I/R)损伤的保护作用及其机制。方法大鼠心肌缺血/再灌注损伤采用冠状动脉左前降支结扎和松开法(LAD法)。实验大鼠随机分为6组:假手术组、模型组、urantide3、10、30μg.kg-13个剂量组,以及1.6mg·kg-1维拉帕米(Verapamil,Ver)阳性药对照组。除假手术组外,其余组别大鼠均实施30min缺血,60min再灌注。受试药于缺血前10min经舌下静脉给药,记录心肌缺血/再灌注过程中各组心率和心电图ST段变化值。实验结束后,测定大鼠血清中MDA、NO的含量以及NOS、LDH的活性;取心脏行伊文思兰和TTC双染色,计算IS/AAR。另取一批大鼠,实验方法同前。实验结束后剪取左心室缺血区,提取蛋白后采用Westernblot方法检测iNOS的蛋白表达情况。结果urantide(10,30μg.kg-1)对心率无明显影响,但可明显抑制缺血/再灌注后心电图ST段的抬高;明显降低血清中MDA的含量和LDH的活性,明显升高血清中NO总量和总的NOS活性;同时明显降低IS/AAR。3μg.kg-1urantide预处理对上述指标均无影响。Westernblot显示urantide(10,30μg.kg-1)能抑制iNOS的表达。结论urantide对心肌缺血/再灌注损伤具有保护作用,作用机制可能与抗脂质过氧化、促进NO合成有关。     

多肽化合物urantide对动脉粥样硬化大鼠胸主动脉和VSMC中Ⅳ型胶原表达的影响

目的：探讨多肽化合物urantide对动脉粥样硬化（AS）大鼠胸主动脉和血管平滑肌细胞（VSMC）中Ⅳ型胶原（Col Ⅳ）表达的影响,阐明其防治AS的作用机制。方法：180只Wistar大鼠随机分为正常对照组（n=30）和AS模型组（n=150）,采用高脂饲料喂养和腹腔注射维生素D₃（VD₃）的方法建立大鼠AS模型。150只AS模型鼠随机分为AS组、氟伐他汀（Flu）组和urantide组（3、7和14 d组）（n=30）。免疫组织化学法检测大鼠胸主动脉壁内Col Ⅳ的表达水平,酶联免疫吸附试验（ELISA）法检测大鼠血清和尿液中羟脯胺酸（HYP）水平。体外培养的VSMC随机分为正常对照组、尾加压素（UⅡ）（10^-8 mol·L^-1）组、Flu组和urantide （10^-10~10^-6 mol·L^-1）组,ELISA法检测各组大鼠VSMC培养上清中Col Ⅳ水平。结果：各组大鼠胸主动脉内膜下不规则斑块内Col Ⅳ表达水平比较差异有统计学意义（F=35.09,P<0.01）。与正常对照组比较,AS组大鼠主动脉中Col Ⅳ表达水平明显升高（P<0.01）;urantide组Col Ⅳ阳性染色强度和范围较AS组均减少（P<0.01）。各组大鼠血清和尿液中HYP水平比较差异有统计学意义（F=24.38,P<0.01;F=26.72,P<0.01）。与正常对照组比较,AS组大鼠血清中HYP水平明显升高（P<0.01）,尿液中HYP水平明显降低（P<0.01）;与AS组比较,urantide组大鼠血清中HYP水平均明显降低（P<0.01）,尿液中HYP水平明显升高（P<0.01）,接近或优于Flu组水平。各组大鼠VSMC培养上清中Col Ⅳ水平比较差异有统计学意义（F=31.04,P<0.01）。与正常对照组比较,UⅡ组大鼠VSMC培养上清中Col Ⅳ水平明显升高（P<0.01）;与UⅡ组比较,urantide组大鼠VSMC培养上清中Col Ⅳ水平明显降低（P<0.05或P<0.01）。结论：urantide可抑制AS大鼠胸主动脉和VSMC中Col Ⅳ的表达,缓解AS病变程度,为临床应用urantide治疗AS提供了实验依据。