Lodenafil treatment in the monocrotaline model of pulmonary hypertension in rats

We assessed the effects of lodenafil on hemodynamics and inflammation in the rat model of monocrotaline-induced pulmonary hypertension (PH). Thirty male Sprague-Dawley rats were randomly divided into three groups: control; monocrotaline (experimental model); and lodenafil (experimental model followed by lodenafil treatment, p.o., 5 mg/kg daily for 28 days) Mean pulmonary artery pressure (mPAP) was obtained by right heart catheterization. We investigated right ventricular hypertrophy (RVH) and IL-1 levels in lung fragments. The number of cases of RVH was significantly higher in the monocrotaline group than in the lodenafil and control groups, as were mPAP and IL-1 levels. We conclude that lodenafil can prevent monocrotaline-induced PH, RVH, and inflammation.     

Cerium oxide nanoparticles attenuate monocrotaline induced right ventricular hypertrophy following pulmonary arterial hypertension

Cerium oxide (CeO₂) nanoparticles have been posited to exhibit potent anti-oxidant activity which may allow for the use of these materials in biomedical applications. Herein, we investigate whether CeO₂ nanoparticle administration can diminish right ventricular (RV) hypertrophy following four weeks of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male Sprague Dawley rats were randomly divided into three groups: control, MCT only (60 mg/kg), or MCT + CeO₂ nanoparticle treatment (60 mg/kg; 0.1 mg/kg). Compared to the control group, the RV weight to body weight ratio was 45% and 22% higher in the MCT and MCT + CeO₂ groups, respectively (p < 0.05). Doppler echocardiography demonstrated that CeO₂ nanoparticle treatment attenuated monocrotaline-induced changes in pulmonary flow and RV wall thickness. Paralleling these changes in cardiac function, CeO₂ nanoparticle treatment also diminished MCT-induced increases in right ventricular (RV) cardiomyocyte cross sectional area, β-myosin heavy chain, fibronectin expression, protein nitrosylation, protein carbonylation and cardiac superoxide levels. These changes with treatment were accompanied by a decrease in the ratio of Bax/Bcl2, diminished caspase-3 activation and reduction in serum inflammatory markers. Taken together, these data suggest that CeO₂ nanoparticle administration may attenuate the hypertrophic response of the heart following PAH.     

不同数目骨髓间充质干细胞移植对大鼠肺动脉高压的作用及内皮素-1表达的影响

目的探讨不同数目骨髓间充质干细胞(mesenchymal stem cells,MSCs)移植对野百合碱(MCT)诱导大鼠肺动脉高压的治疗作用,以及对内皮素-1(endothelin-1,ET-1)表达的影响。方法成年雄性Wistar大鼠40只(体重180～250 g),按随机数字表法分为4组,每组10只。A组:大鼠腹腔注射MCT 60 mg/kg,经颈外静脉注入1×106MSCs;B组:大鼠腹腔注射MCT 60 mg/kg,经颈外静脉注入5×105MSCs;MCT组:大鼠腹腔注射MCT60 mg/kg和等量磷酸盐缓冲液(PBS);对照组:大鼠腹腔注入等量生理盐水和等量PBS。MSCs移植4周后测定右心室收缩压(RVSP),计算心室比,即右心室/(左心室+室间隔)[RV/(LV+VS)];观察肺组织形态学改变;检测肺组织ET-1基因表达和血清ET-1的含量。结果 MSCs移植4周后,A组RVSP和RV/(LV+VS)与MCT组比较明显降低[(35.8±4.2)mm Hg vs.(47.2±10.1)mm Hg,P<0.01;(0.357±0.032)vs.(0.452±0.056),P<0.01];而B组与MCT组比较差异无统计学意义(P>0.05)。A组肺小动脉中膜厚度较MCT组明显变薄[(19.7%±3.0%)vs.(26.8%±3.6%),P<0.01];而B组则差异无统计学意义。逆转录酶-聚合酶链反应(RTase-PCR)检测结果显示,MCT组肺组织ET-1 mRNA表达最强,A组肺组织ET-1 mRNA与MCT组比较明显减弱,B组表达与MCT组接近。A组血清ET-1含量与MCT组比较明显减少。结论 MSCs静脉移植对MCT诱导的肺动脉高压具有抑制作用,并能减少肺组织ET-1的mRNA表达及血清ET-1浓度。采用1×106MSCs移植具有较好的治疗作用。     

雷米普利通过调节细胞外调节激酶1/2的活性抑制肺动脉高压大鼠肺血管重构

目的探讨雷米普利抑制野百合碱（MCT）诱导的肺动脉高压（PAH）大鼠肺血管重构是否与调节细胞外调节激酶1/2（ERK1/2）活性有关。方法雄性Sprague-Dawley大鼠30只,质量280～320g,随机分为：正常对照组、PAH组、PAH＋雷米普利组。PAH组和PAH＋雷米普利组一次性颈部注射MCT60mg/kg后,PAH＋雷米普利组用雷米普利灌胃,PAH组用生理盐水灌胃。对照组颈部注射生理盐水后,用生理盐水灌胃。4周后,测定大鼠的右室收缩压（RVSP）和右心室肥厚指数（RVHI）,并用图像分析软件,测定肺小动脉管壁厚度（WT）占动脉外径（ED）的百分比（WT,%）及管壁面积（WA）占血管总面积的百分比（WA,%）。放射免疫法检测肺组织中血管紧张素Ⅱ（AngⅡ）浓度。Western免疫印迹分析肺组织中ERK1/2磷酸化水平。结果PAH组的RVSP、RVHI、WT（%）、WA（%）、肺组织AngⅡ浓度和ERK1/2磷酸化水平均显著高于正常对照组;雷米普利组RVSP、RVHI、WT（%）、WA（%）、肺组织AngⅡ浓度和ERK1/2磷酸化水平均明显低于PAH组。结论雷米普利抑制MCT诱导的肺血管重构的机制可能与降低肺组织ERK1/2磷酸化水平有关。     

人参皂苷Rg2对野百合碱诱导肺动脉高压模型大鼠的作用

目的 探讨人参皂苷Rg2(ginsenoside-Rg2)对野百合碱(monocrotaline,MCT) 诱导的肺动脉高压(pulmonary arterial hypertension,PAH) 模型大鼠的作用.方法 将48只雄性SD 大鼠随机分为对照组、模型组、人参皂苷Rg2 (20、40、80 mg/kg) 组和波生坦(Bos,200 mg /kg) 组,每组8只.一次性腹腔注射MCT(50 mg/kg) 复制PAH 模型,此后按分组灌胃给药,每天1 次,连续28d.通过颈总动脉和右心室用八道生理记录仪测定右心室收缩压(right ventricle systolic pressure,RVSP)、平均动脉压(mean arterial blood pressure,MBP)、心率(heart rate,HR).处死动物后采集血浆测定内皮素-1(endothelin-1,ET-1)和一氧化氮(nitric oxide,NO)的水平并测定右心肥大指数.结果 野百合碱注射后第28天时,与对照组比较,模型组右心室压力、右心肥大指数明显升高,心率和平均动脉压明显减小;血浆ET-1水平明显增加,NO水平明显降低.人参皂苷Rg2能明显缓解这些变化.结论 人参皂苷Rg2对野百合就所致的肺动脉高压模型大鼠具有改善作用.     

骨髓间充质干细胞治疗实验性肺动脉高压后肺组织结构的变化

目的： 探讨骨髓间充质干细胞(MMSCs）移植治疗肺动脉高压(PAH)后肺组织超微结构的变化。方法: 取SD大鼠的骨髓,经贴壁筛选法体外培养并纯化MMSCs,用Hoechst 33342荧光染料标记。实验动物随机分为3组: MMSCs移植治疗组（M组）、肺动脉高压模型组 (H组)和正常对照组 (C组)。M组采用野百合碱(50 mg·kg-1) 注射复制PAH模型成功后3周经舌下静脉移植5×109 cells/L MMSCs细胞悬液1 mL;H组复制PAH模型后3周移植 1 mL L-DMEM细胞培养液,C组在同时间注射等量L-DMEM液。饲养4周,观察各组动物一般情况、生存率、右心室收缩压、右心指数及肺小动脉的微观结构和超微结构的改变。结果: 实验动物移植MMSCs后,生存状况明显改善,食欲及活动增加,毛色顺滑、光亮,动物存活率为100％;而模型组动物活动明显减少、食欲下降,消瘦,体重下降或不增,在1月内相继死亡,死亡率为100％。各项指标检测结果显示,MMSCs移植组（M组）大鼠较单纯肺动脉高压组 (H组)右心室收缩压明显降低［移植组为(32.20±2.32)mmHg,而模型组为(48.30±1.56)mmHg,两者相比差异显著,P<0.05］,右心指数下降［移植组为(38.80±3.24)%,模型组为(45.10±3.43)%, 二者相比差异显著,P<0.05］,肺小动脉的重建和超微结构的血气屏障、线粒体、板层小体等改变均有明显改善,其结果接近正常对照组。结论: MMSCs移植后可通过形成新生血管建立侧枝循环,有效减轻野百合碱诱导的肺动脉高压和肺组织病变程度。     

血管紧张素-（1-7）对野百合碱诱导的肺动脉高压和肺血管重构的影响

目的： 探讨血管紧张素-（1-7）［Ang-(1-7)］对野百合碱(MCT)诱导的肺动脉高压(PAH)模型中肺动脉压力和肺小动脉重构的影响。方法: 雄性Sprague-Dawley大鼠60只,随机分为:对照组、PAH组、PAH +Ang-(1-7)组。PAH 组和PAH+Ang-(1-7)组一次性颈部注射MCT60 mg/kg,24 h后经微泵持续泵入生理盐水或Ang-(1-7)(24 μg·kg-1·h-1)共4周。对照组一次性颈部注射相同体积的生理盐水,24 h后泵入生理盐水。4周后,测定大鼠的右室收缩压(RVSP)和右心室肥厚指数(RVHI),并运用图像分析软件,测定肺小动脉管壁厚度(WT)占动脉外径(ED)的百分比(WT %)及管壁面积(WA)占血管总面积的百分比(WA%)。通过放射免疫方法检测肺组织中一氧化氮(NO)浓度。 Western blotting分析肺组织内皮一氧化氮合酶(eNOS)和eNOS Ser1177-phosphorylation 的表达。 结果: PAH组与对照组相比,RVSP、RVHI、WT%、WA%明显升高（P<0.01）,肺组织中NO浓度、eNOS、eNOS Ser1177-phosphorylation 的表达水平显著降低（P<0.01）;Ang-(1-7)干预后RVSP、RVHI、WT%、WA %明显降低（P<0.01）,肺组织NO浓度、eNOS、eNOS Ser1177-phosphorylation 的表达明显升高（P<0.01）。结论: 在MCT诱导的肺动脉高压模型中,Ang-(1-7)可预防肺动脉高压的发生,同时抑制肺血管的重构,其机制可能与Ang-(1-7)升高肺组织NO浓度,上调eNOS的表达以及eNOS Ser1177-phosphorylation 水平有关。     

辛伐他汀对失代偿右心衰竭大鼠心肌氧化应激的影响

目的:观察辛伐他汀(Sim)对野百合碱(MCT)引起的失代偿右心衰竭大鼠心肌的氧化应激的影响。方法:一次性皮下注射MCT制备大鼠右心衰竭模型。注射MCT两周后,灌胃给予Sim或蒸馏水(对照组)治疗14d。测定各组大鼠右室心肌匀浆中的SOD和GSH-PX酶活力及MDA含量,以及肝和肺组织的湿重和干重的比值。结果:与正常大鼠比较,对照组大鼠右室心肌SOD和GSH-PX酶活力显著下降,心肌MDA含量及肝、肺湿重和干重的比值明显升高,(P<0.01)。Sim可有效地抑制MCT引起的心肌SOD和GSH-PX酶活力的下降及MDA含量的增加(P<0.01),并使肝、肺湿重和干重的比值降低。结论:Sim对MCT引起的失代偿右心衰竭大鼠心肌的氧化应激具有抑制作用。     

DA-8159, a potent cGMP phosphodiesterase inhibitor,attenuates monocrotaline-induced pulmonary hypertension in rats

In this study, we evaluated the effects of oral administration of DA-8159, a selective phosphodiesterase-5 inhibitor, on the development of pulmonary hypertension (PH) induced by monocrotaline (MCT). Rats were administered either MCT (60 mg/kg) or saline. MCT-treated rats were divided into three groups and received orally administered vehicle, or 1 mg/kg or 5 mg/kg of DA-8159, twice a day for twenty-one days. The MCT group demonstrated increased right ventricular weights, medial wall thickening in the pulmonary arteries, myocardial fibrosis and the level of plasma cyclic guanosine monophosphate (cGMP), along with decreased body weight gains. However, DA-8159 markedly and dose-dependently reduced the development of right ventricular hypertrophy and medial wall thickening. DA-8159 also amplified the increase in plasma cGMP level and significantly increased the level of lung cGMP, compared with the MCT group. Although the body weight gain was still lower from the saline-treated control group, DA-8159 demonstrated a significant increase in body weight gains, in both 1 mg/kg and 5 mg/kg groups, when compared with the MCT group. In myocardial morphology, MCT-induced myocardial fibrosis was markedly prevented by DA-8159. These results suggest that DA-8159 may be a useful oral treatment option for PH.     

Liver inflammation during monocrotaline hepatotoxicity

Monocrotaline (MCT) is a pyrrolizidine alkaloid (PA) plant toxin that causes hepatotoxicity in humans and animals. Human exposure occurs from consumption of contaminated grains and herbal teas and medicines. Intraperitoneal injection (i.p.) of 300 mg/kg MCT in rats produced time-dependent hepatic parenchymal cell (HPC) injury beginning at 12 h. At this time, an inflammatory infiltrate consisting of neutrophils (PMNs) appeared in areas of hepatocellular injury, and activation of the coagulation system occurred. PMN accumulation was preceded by up-regulation of the PMN chemokines cytokine-induced neutrophil chemoattractant-1 (CINC-1) and macrophage inflammatory protein-2 (MIP-2) in the liver. The monocyte chemokine, monocyte chemoattractant protein-1 (MCP-1), was also upregulated. Inhibition of Kupffer cell function with gadolinium chloride (GdCl₃) significantly reduced CINC-1 protein in plasma after MCT treatment but had no effect on hepatic PMN accumulation. Since inflammation can contribute to either pathogenesis or resolution of tissue injury, we explored inflammatory factors as a contributor to MCT hepatotoxicity. To test the hypothesis that PMNs contribute to MCT-induced HPC injury, rats were depleted of PMNs with a rabbit anti-PMN serum prior to MCT treatment. Anti-PMN treatment reduced hepatic PMN accumulation by 80% but had no effect on MCT-induced HPC injury or activation of the coagulation system. To test the hypothesis that Kupffer cells and/or tumor necrosis factor- (TNF-) are required for MCT-induced HPC injury, rats were treated with either GdCl₃ to inhibit Kupffer cell function or pentoxifylline (PTX) to prevent synthesis of TNF-. Neither treatment prevented MCT-induced HPC injury. Results from these studies suggest that PMNs, Kupffer cells and TNF- are not critical mediators of MCT hepatotoxicity. Accordingly, although inflammation occurs in the liver after MCT treatment, it is not required for HPC injury and possibly occurs secondary to hepatocellular injury.