间歇性低压低氧对大鼠肺动脉高压的预防作用及血管保护机制

发布时间：2018-01-16 06:05

本文关键词：间歇性低压低氧对大鼠肺动脉高压的预防作用及血管保护机制　出处：《河北医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的:近年来人们逐渐认识到,高原上长期低氧的环境可增加心脏对缺血损伤的抵抗力。然而,长期慢性的持续性高原低氧又对机体有很多不利的作用,如右心室肥厚及红细胞增多症。大量研究表明,间歇性低压低氧(Intermittent Hypopiesia Hy Poxia,IHH)除具有慢性持续性低氧的心脏保护作用外,对机体的不良影响也非常低,同时,间歇性低压低氧又是临床低氧的常见形式,如冠心病、睡眠呼吸暂停综合症。因此,IHH日益受到人们的关注。已有研究表明,IHH对机体有很多益处,例如可保护神经及肝脏等器官组织,对慢性阻塞性支气管炎及支气管哮喘有一定辅助治疗作用,也有文献报道IHH可对抗缺血/再灌注所致心功能损伤及心律失常,增强机体对缺血、缺氧的耐受性,但未见对肺动脉高压具有预防及保护作用的研究报道。本实验采用野百合碱(monocrotaline,MCT)诱导雄性SD大鼠肺动脉高压模型,观察IHH对动物模型肺组织及肺血管功能学、形态学的作用,并初步探讨其对肺血管的保护机制,为临床治疗PAH提供新的实验及理论依据。方法:由河北医科大学动物实验研究中心提供的清洁级健康雄性SD大鼠40只,质量(150-200)g,随机分为4组,即正常对照组(CON组)、肺动脉高压组(PAH组)、间歇性低压低氧处理组(IHH组)、IHH+MCT组。CON组的大鼠不进行任何处理,正常饲养28天后直接进行右心室收缩压(right heart systolic pressure,RVSP)和平均肺动脉压力(mean pulmonary artery pressure,m PAP)的测定,计算右心室肥厚指数(right ventricular hypertrophy index,RVHI)并行血管环灌流实验观察血管反应性的改变。PAH组经腹腔注射MCT14天后测RVSP及m PAP,计算RVHI并观察血管反应性的改变。IHH组接受模拟5km海拔高度,每天6h的间歇性低压低氧处理28d后检测RVSP、m PAP,计算RVHI并观察血管反应性的改变。IHH+MCT组先经受28d的IHH后腹腔注射MCT,14天后检测RVSP、m PAP,计算RVHI并观察血管反应性的改变。所有实验数据均采用SPSS 13.0统计软件进行统计学分析,实验结果均为服从正态分布的计量资料,结果以均数±标准差表示。四组数据之间的比较运用单因素方差分析(One-way ANOVA),检验水准α=0.05,P0.05为差异有统计学意义。结果:1实验动物的死亡情况与一般生长状况1.1死亡情况PAH组死亡2只大鼠,其余各组大鼠均全部存活。1.2一般生长情况PAH组大鼠从腹腔注射MCT后第2周开始体重较CON组减轻,活动量也明显减少,倦卧,喘促,进食量减少。IHH组大鼠的活动度、进食状况及重量均较同期的PAH组有所改善,但较CON组差。大鼠开胸后肉眼可见PAH组大鼠的右心室明显增厚,肺部淤血肿胀,部分伴有胸水、腹水,甚至心包积液。2血流动力学结果2.1各组大鼠m PAP的结果PAH组的m PAP明显高于其他三组,差异均有统计学意义;IHH+MCT组大鼠的m PAP较PAH组显著降低,差异有统计学意义(IHH+MCT:19.45±1.03 vs PAH:35.28±0.94mm Hg,P0.05);其较CON组的压力水平偏高,但无统计学差异(IHH+MCT:19.45±1.03 vs CON:16.42±0.46mm Hg,P0.05);IHH组的m PAP与CON组相比稍偏高,但无统计学意义(IHH:17.86±0.42 vs CON:16.42±0.46mm Hg,P0.05)。2.2各组大鼠RVSP的结果PAH组的RVSP明显高于其他三组,差异均有统计学意义(PAH:45.14±0.62 vs CON:24.46±1.21mm Hg,P0.05);IHH+MCT组较PAH组显著降低,差异有统计学意义(IHH+MCT:27.58±0.98 vs PAH:45.14±0.62mm Hg,P0.05),其与CON组的压力水平相比偏高,但无统计学意义(IHH+MCT:27.58±0.98 vs CON:24.46±1.21mm Hg,P0.05)。IHH组与CON组相比偏高,但无统计学意义(IHH:25.74±1.16 vs CON:24.46±1.21mm Hg,P0.05)。3右心室肥厚指数(RVHI)的计算PAH组的RVHI明显高于其他三组;与CON相比,野百合碱注射后2周,PAH组大鼠的RVHI明显升高(PAH:48.76±11.7 vs CON:24.43±3.79,P0.05)。IHH+MCT组大鼠的RVHI较PAH组显著降低,差异有统计学意义(IHH+MCT:25.61±4.18 vs PAH:48.76±11.7,P0.05);其与CON组的压力水平相比偏高,但尚未达到CON组的压力水平,差异无统计学意义(IHH+MCT:25.61±4.18 vs CON:24.43±3.79,P0.05);IHH组的RVHI与CON组相比偏高,但无统计学意义(IHH:27.66±4.17vs CON:24.43±3.79,P0.05)。4低压低氧对肺动脉内皮功能的作用在四个实验组中,苯肾上腺素Phenylephrine(PHE)从10-8mol/L到10-5mol/L均可引起血管的内皮依赖性收缩反应,乙酰胆碱Acetylcholine(ACH)从10-8mol/L到10-5mol/L都可引起血管的内皮依赖性舒张反应,硝普钠Sodium nitropmsside(SNP)从10-8mol/L到10-5mol/L均可引起血管的非内皮依赖性舒张反应,且以上实验药物对血管的收缩及舒张作用都具有浓度依赖性。MCT所诱导的PAH大鼠肺动脉的内皮依赖性血管收缩及舒张反应、非内皮依赖性血管舒张反应较CON组均明显受损,差异有统计学意义(P0.05);而IHH干预后,可显著改善其受损的内皮依赖性的血管收缩及舒张反应、非内皮依赖性的血管舒张反应,差异有统计学意义(P0.05)。结论:1 SD大鼠经腹腔注射野百合碱后14天即能形成明显的肺动脉高压模型。2间歇性低压低氧能够有效降低野百合碱诱导的肺动脉高压大鼠升高的平均肺动脉压及右心室收缩压。3间歇性低压低氧能够有效减轻野百合碱诱导的肺动脉高压大鼠的右心室肥厚。4间歇性低压低氧对肺动脉高压大鼠肺血管的内皮依赖性血管收缩及舒张反应、非内皮依赖性血管舒张反应均具有重要保护作用。
[Abstract]:Objective: in recent years, people gradually realize that the plateau hypoxia environment can increase the long-term cardiac resistance to ischemic injury. However, chronic persistent hypoxia and have many adverse effects on the body, such as right ventricular hypertrophy and polycythemia. Many studies show that intermittent hypobaric hypoxia (Intermittent Hypopiesia Hy Poxia, IHH) in the heart has a protective effect of chronic persistent hypoxia, adverse effects on the body is also very low, at the same time, intermittent hypobaric hypoxia is a common form of clinical hypoxia such as coronary heart disease, sleep apnea syndrome. Therefore, IHH has attracted more and more attention. Studies have shown that IHH has many benefits on the body, for example, can protect the nerve and liver and other organs, have a certain role in adjuvant therapy of chronic obstructive bronchitis and bronchial asthma, also reported against ischemia / IHH Reperfusion injury and arrhythmia caused by heart function, enhance the body of ischemia, hypoxia tolerance, but no report has preventive and protective effects on pulmonary hypertension. This experiment used monocrotaline (monocrotaline, MCT) - induced pulmonary arterial hypertension in male SD rats model, observe the effect of IHH on the animal model of lung tissue pulmonary vascular function and morphology, function, and explore the protective mechanism of pulmonary artery, and provide experimental and theoretical basis for the clinical treatment of PAH. The new method provided by the research center of Hebei Medical University animal clean grade healthy male SD 40 rats, the quality of (150-200) g, were randomly divided into 4 groups that is, the normal control group (CON group), pulmonary hypertension group (PAH group), intermittent hypoxia group (IHH group), IHH+MCT group and.CON group rats without any treatment, normal feeding after 28 days of right ventricular systolic pressure (right hear T systolic pressure, RVSP) and the mean pulmonary arterial pressure (mean pulmonary artery pressure, m PAP) were calculated, the right ventricular hypertrophy index (right ventricular hypertrophy index, RVHI) parallel vascular ring perfusion experiment to observe the changes of vascular reactivity in.PAH group by abdominal cavity injection of MCT14 RVSP and m PAP days after the test, the calculation of RVHI and change the.IHH group to observe the vascular reactivity of 5km received simulated altitude hypoxia after 28d intermittent 6h daily detection of RVSP, m PAP, RVHI and.IHH+MCT group to observe the change of the calculation of vascular reactivity to undergo 28d IHH after intraperitoneal injection of MCT, 14 days after the detection of RVSP, m PAP, RVHI and vascular calculation the response of the experiment. All the data were used SPSS 13 statistical software for statistical analysis, the experimental results are subject to the normal distribution of the measurement data, the mean standard deviation of the data between the four groups said. Compared with single factor analysis of variance (One-way ANOVA), a =0.05 level test P0.05, the difference was statistically significant. Results: the death of 1 experimental animal and the general growth of the 1.1 death deaths in group PAH 2 rats, the rats were survived.1.2 growth from the abdominal cavity of rats in the PAH group after MCT injection second week weight compared with the CON group activity, also significantly reduced, tired lying, dyspnea, reduced food intake of rats in the.IHH group activity, group PAH feeding condition and weight were compared to the same period has improved, but compared with the CON group. Right ventricular thickening visible in PAH rats the rats after thoracotomy, pulmonary congestion and swelling, accompanied by ascites, pleural effusion, pericardial effusion and even.2 hemodynamic results of 2.1 rats in each group were m PAP m PAP in the PAH group was significantly higher than that of the other three groups, there were statistically significant differences; the rats in group IHH+MCT than in group PAH m PAP Significantly, the difference was statistically significant (IHH+MCT:19.45 + 1.03 vs PAH:35.28 + 0.94mm Hg, P0.05); the CON group stress level is high, but the difference was not statistically significant (IHH+MCT:19.45 + 1.03 vs CON:16.42 + 0.46mm Hg, P0.05); m PAP and CON group in the IHH group was slightly higher, but there was no statistical significance (IHH:17.86 + 0.42 vs CON:16.42 + 0.46mm Hg, P0.05).2.2 rats RVSP results in the PAH group, RVSP was significantly higher than the other three groups, the differences were statistically significant (PAH:45.14 + 0.62 vs CON:24.46 + 1.21mm Hg, P0.05); group IHH+MCT was significantly lower than that of PAH group, the difference was statistically significant (IHH+MCT:27.58 + 0.98 vs PAH:45.14 + 0.62mm Hg, P0.05 and CON), the group compared to the level of pressure is high, but there was no statistical significance (IHH+MCT:27.58 + 0.98 vs CON:24.46 + 1.21mm Hg, P0.05).IHH group and CON group compared to the high side, but with no statistical significance (IHH:25.74 + 1.16 vs CON:24.46 + 1.2 1mm Hg P0.05.3), right ventricular hypertrophy index (RVHI) calculation of PAH of group RVHI was significantly higher than the other three groups; compared with CON, 2 weeks after monocrotaline injection, rats in PAH group were significantly increased (RVHI PAH:48.76 + 11.7 vs CON:24.43 + 3.79, P0.05) of.IHH+MCT rats was significantly higher than that of RVHI PAH group decreased, the difference was statistically significant (IHH+MCT:25.61 + 4.18 vs PAH:48.76 + 11.7, P0.05); and CON group compared to the level of high pressure, but the pressure has not yet reached the level of CON group, the difference was not statistically significant (IHH+MCT:25.61 + 4.18 vs CON:24.43 + 3.79, P0.05); IHH RVHI group compared with CON group., but there was no statistical significance (IHH:27.66 + 4.17vs CON:24.43 + 3.79, P0.05).4 hypobaric hypoxia on pulmonary artery endothelial function in four experimental groups, Phenylephrine phenylephrine (PHE) from 10-8mol/L to 10-5mol/L can cause vascular endothelium dependent contractile response to acetylcholine. Base Acetylcholine (ACH) from 10-8mol/L to 10-5mol/L can cause vascular endothelium-dependent relaxation, sodium nitroprusside Sodium nitropmsside (SNP) - from 10-8mol/L to 10-5mol/L can induce endothelial vascular endothelial dependent relaxation and contraction and diastolic function above the experimental drug on blood vessels is dependent on the concentration of pulmonary artery induced by.MCT PAH rats dependent vasoconstriction and vasodilation, endothelium dependent vasodilation in CON group were significantly impaired, the difference was statistically significant (P0.05); and the intervention of IHH reaction can significantly improve the impaired endothelium-dependent vascular contraction and relaxation, non endothelium dependent vasodilation. The difference was statistically significant (P0.05). Conclusion: 1 SD rats by intraperitoneal injection of monocrotaline after 14 days can form obvious.2 intermittent pulmonary hypertension model of low pressure and low oxygen can be effectively reduced Right ventricular hypertrophy endothelial.4 intermittent hypobaric hypoxia in rats with pulmonary arterial hypertension induced by monocrotaline low elevated mean pulmonary artery pressure and right ventricular systolic pressure.3 intermittent hypobaric hypoxia can effectively reduce rat pulmonary hypertension induced by monocrotaline on pulmonary vascular of rats with pulmonary hypertension dependent vasoconstriction and vasodilation and non endothelium dependent vasodilation has important protective effects.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R544.1

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