苹果多酚对野百合碱诱导的肺动脉高压大鼠肺血管重构的作用和机制*

目的:探讨苹果多酚抑制肺动脉高压大鼠肺动脉血管重构的作用及其机制。方法:雄性SD大鼠随机分为对照组(Con),野百合碱(MCT)组,苹果多酚(APP)组,野百合碱+苹果多酚(MCT+APP)组,每组9只。Con组:每天皮下注射1 ml生理盐水;APP组:隔天按20 mg/kg的剂量腹腔注射苹果多酚;MCT组:按60 mg/kg剂量一次性皮下注射MCT;MCT+APP组:一次性皮下注射60 mg/kg剂量MCT,隔天按20 mg/kg剂量腹腔注射APP,所有处理持续3周。建模完成后,检测各组大鼠平均肺动脉压(mPAP),肺血管阻力(PVR),右心室肥厚指数(RVHI),肺动脉血管环外周长比值(WT%),肺小血管管壁面积和管总面积比值(WA%)。检测肺组织中的白细胞介素1(IL-1),白细胞介素6(IL-6),肿瘤坏死因子α(TNF-α),环氧化酶2(COX-2),髓过氧化物酶(MPO) 等炎症通路相关指标,及肺动脉平滑肌细胞内Ca²⁺和内皮细胞eNOS,NO含量。结果:MCT组大鼠与对照组比较,在动物水平的指标mPAP、PVR、RVHI、WA%、WT%和肺动脉组织内IL-1,IL-6,TNF-α,COX-2,MPO表达量以及肺动脉平滑肌细胞内的Ca^{2 +}浓度明显升高(P＜0.05),而内皮细胞中的eNOS,NO含量明显下降( P＜0. 05) ;苹果多酚治疗组与MCT组大鼠相比上述情况得到改善,其中COX-2和Ca²⁺指标明显下降,且具有统计学意义(P＜0. 05)。结论:苹果多酚可通过抑制MCT引起的肺组织内IL-1,IL-6 ,TNF-α,COX-2升高和肺动脉平滑肌细胞内Ca^{2 +}升高以及内皮细胞中eNOS,NO降低,抑制平滑肌细胞增殖,逆转肺血管重构,缓解肺动脉高压。

Effects of apple polyphenols on monocrotaline-induced pulmonary vascular remodeling in rats and its mechanism

Objective: To investigate the effects of apple polyphenols on pulmonary vascular remodeling in rats with pulmonary arterial hypertension and its mechanism. Methods: Rats were randomly divided into 4 groups:control (Con) group, monocrotaline (MCT) group, apple polyphenol (APP) group,monocrotaline + apple polyphenol (MCT+APP) group. In Con group, rats received a subcutaneous injection of physical saline. In APP group, rats received intraperitoneal injection of 20 mg/kg APP, every other day. In MCT group, rats received a single subcutaneous injection of MCT(60 mg/kg). In MCT+APP group, rats received subcutaneous injection of 60 mg/kg MCT followed by an intraperitoneal injection of 20 mg/kg APP every other day. All the disposal lasted 3 weeks. Then the PAH-relevant indicators, such as mean pulmonary artery pressure(mPAP), pulmonary vascular resistance(PVR), right ventricular hypertrophy index (RVHI) ,wall thickness (WT%) and wall area (WA%) were tested. After that, the inflammatory pathway related indicators, such as interleukin1(IL-1),interleukin1(IL-6), tumor necrosis factor α(TNF-α), cyclooxygenase 2(COX-2) and myeloperoxidase(MPO) in pulmonary tissue and free intracellular Ca²⁺ in pulmonary smooth muscle cell(PASMC), content of eNOS and NO in endothelial cells were determined. Results: Compared with the control group, the levels of mPAP, PVR, RVHI, WA%, WT%, and IL-1, IL-6, TNF-α, COX-2, MPO in tissue and the expression of Ca^{2 +} in PASMC of MCT group were increased significantly, while the contents of eNOS and NO in endothelial cells were decreased significantly (P＜0.05). Compared with the MCT group, the apple polyphenol treatment could improve the above mentioned situation, and the COX-2 and Ca²⁺ indicators of the apple polyphenol treatment group were decreased significantly (P＜0.05). Conclusion: MCT can increase COX-2 expression and intracellular Ca²⁺ in pulmonary artery smooth muscle cells, decrease the contents of eNOS and NO in endothelial cells, while apple polyphenols can significantly inhibit these effects.