苹果多酚通过下调钙敏感受体改善大鼠低氧性肺动脉高压的作用

目的：探究苹果多酚通过下调钙敏感受体（CaSR）表达改善大鼠低氧性肺动脉高压的作用。方法：36只雄性SD大鼠随机分为对照组、低氧诱导组和苹果多酚干预组（n=12）。低氧诱导组和苹果多酚干预组大鼠每天在低氧舱（氧浓度为10%）中间断低氧暴露8 h，对照组在正常环境下饲养，为期四周。建模同时，苹果多酚干预组每日用苹果多酚按200 mg/kg的剂量灌胃，对照组、低氧诱导组用等量生理盐水灌胃，每日1次，共持续四周。建模完成后，检测各组大鼠的肺动脉平均压（mPAP）、肺血管阻力（PVR）、右心室肥厚指数（RVHI）、肺动脉中膜厚度（MT）、WA%、WT%及肺动脉组织中CaSR表达量。结果：低氧暴露组大鼠mPAP、PVR、RVHI、MT、WA%、WT%及肺动脉组织中CaSR表达量均较对照组明显升高（P<0.01）；苹果多酚干预组可改善上述效应。结论：苹果多酚能有效预防大鼠低氧性肺动脉高压，其机制与下调CaSR的表达有关。

Improvement effects of applephenon on hypoxia pulmonary hypertension in rats by down-regulating the calcium sensing receptor

Objective: To investigate the improving effect of applephenon on the hypoxic-pulmonary hypertension by down-regulating the expression of calcium sensing receptor(CaSR).Methods: Thirty-six male SD rats were randomly divided into 3 groups(n=12):control group, hypoxia-exposure group and applephenon-intervention group.Rats in hypoxia-exposure group and applephenon-intervention group were intermittently exposed to hypoxia in a hypoxic-cabin (the O₂ concentration was 10%) for 8 hours everyday, while rats in control group were raised in normal environment, the experiments were conducted for 4 weeks.Meanwhile, rats in applephenon-intervention group were given intragastrically with applephenon according to 200 mg/kg per day, rats in control and hypoxia-exposure group were given intragastrically with the same amount of normal saline, it lasted for 4 weeks. Then the average pulmonary artery pressure(mPAP), pulmonary vascular resistance(PVR), right ventricular hypertrophy index(RVHI), medial thickness(MT), WA%, WT% and the expression of calcium sensitive receptor (CaSR) of rats in each group were measured.Results: mPAP, PVR, RVHI, MT, WA%, WT% and CaSR expression in hypoxia-exposure group were all significantly higher than those in control group(P<0.01), while applephenon could improved those obviously.Conclusion: Applephenon has a good prophylactic effect on hypoxic pulmonary hypertension, the mechanism may be involved in the down-regulation of CaSR expression.