慢性间歇性低压低氧对内源性大麻素类物质anandamide心脏保护作用的影响

发布时间：2018-04-16 21:16

  本文选题：慢性间歇性低压低氧 + anandamide　； 参考：《河北医科大学》2011年硕士论文

【摘要】：目的:大量研究表明,慢性间歇性低压低氧(Chronic intermittent hypobaric hypoxia, CIHH)具有明显的心脏保护作用,可增强心脏对缺血、缺氧的耐受性,减轻缺血/再灌注对心肌的损伤,促进缺血/再灌注后心脏舒缩功能的恢复,以及抗心律失常。有研究报道,CIHH可改变机体对某些药物的反应性,从而间接发挥作用。Anandamide(AEA)是一种内源性大麻素物质,具有抗心肌缺血、抗心律失常等心脏保护作用。但不知CIHH对AEA心脏保护作用有何影响。本研究旨在利用大鼠离体心脏缺血/再灌模型,观察CIHH对AEA抗心肌缺血/再灌损伤保护作用的影响,并探讨其机制。 方法:雄性成年Sprague-Dawlay(SD)大鼠随机分为5组:间歇性低氧14天组(CIHH14)、间歇性低氧28天组(CIHH28)、anandamide组(AEA)、间歇性低氧14天加AEA组(CIHH14+AEA)和对照组(CON)。CIHH组和CIHH+AEA大鼠置于低压氧舱,分别接受14天、28天模拟5000米海拔高度(PB=404 mmHg, PO2=84 mmHg)的低氧处理,每天6小时。AEA和CON组大鼠除了不接受低氧处理外,其它处理均与间歇性低氧组动物相同。 大鼠麻醉固定,迅速开胸,取出心脏,应用Langendorff离体心脏灌流装置制备心肌缺血/再灌注模型,即首先稳定灌流30 min,停灌30 min(缺血),然后复灌60 min(再灌注)。将液体小囊插入左心室,室内压力通过压力换能器输入记录系统,分别描记离体大鼠心脏基础状态和缺血/再灌注状态下不同时间的心脏功能的变化。心功能指标包括:左室发展压(left ventricular systolic pressure, LVDP)、左室舒张末压(left ventricular end diastolic pressure, LVEDP)和左室压力最大变化速率(maximal positive and negative velocity of left ventrichlar pressure,±LVdp/dtmax)。 对离体大鼠心脏,分别在缺血前给予不同的药物干预。⑴对AEA和CIHH14+AEA组大鼠离体心脏,在缺血前给予10 min的AEA(2 nM)预处理;⑵对部分CIHH14+AEA大鼠离体心脏,在给AEA前分别给予10 min的AEA CB2受体阻断剂AM630(10 nM)和CB1受体阻断剂AM251(10 nM)预处理;⑶对部分CON大鼠离体心脏在缺血前分别给予10 min的AM630(10 nM)和AM251(10 nM)预处理。 实验过程中,留取各监测时间点心脏灌流漏出液(冠脉流量),利用分光光度计按照乳酸脱氢酶试剂盒方法测定其中乳酸脱氢酶(lactate dehydrogenase, LDH)含量。实验结束后,取下心脏,置于液氮中冰冻保存。通过黄嘌呤氧化酶法方法,测定左心室心肌中超氧化物岐化酶(superoxide dismudase, SOD)活力,通过硫代巴比妥酸法计算出丙二醛(malondialdehyde, MDA)含量。 结果:⑴基础状态下,CIHH14、CIHH28、AEA、CIHH14+AEA和CON大鼠的LVDP分别为132.1±9.7、132.0±12.8、135.5±8.6、131.6±8.5和132.2±11.0;LVEDP分别为5.5±2.9、5.6±1.8、7.8±5.7、5.8±3.3和5.7±2.6;+LVdp/dtmax分别为3606.4±97.1、3616.8±109.2、3610.3±116.8、3586.6±90.4和3617.3±97.9 ; -LVdp/dtmax分别为2536.4±87.9、2612.0±46.4、2498.4±96.4、2480.4±63.0和2500.4±80.4,各组心功能参数间均无明显差异(P0.05)。 ⑵缺血后、再灌注60 min时,CIHH28和CIHH14+AEA大鼠的LVDP恢复分别为52.7±6.5%和53.1±8.5%,两者间无显著差异(P0.05),但明显好于CIHH14大鼠的11.2±5.9%、AEA大鼠的8.9±5.3%和CON大鼠的10.4±4.0%(P0.01);LVEDP的恢复在CIHH28和CIHH14+AEA大鼠分别为48.3±12.3%和42.1±11.5%,两者间无显著差异(P0.05),但明显好于CIHH14大鼠的14.5±10.2%、AEA大鼠的15.7±9.7%和CON大鼠的15.6±9.1%(P0.05);+LVdp/dtmax的恢复在CIHH28和CIHH14+AEA大鼠分别为38.1±2.2%和38.2±2.4%,两者间无显著差异(P0.05),但明显好于CIHH14大鼠的8.6±1.5%、AEA大鼠的8.3%±1.1%和CON大鼠的8.5±1.5%(P0.05);-LVdp/dtmax的恢复在CIHH28和CIHH14+AEA大鼠分别为41.8±2.4%和40.5±1.3%,两者间无显著差异(P0.05),但明显好于CIHH14大鼠的11.2±1.7%、AEA大鼠的11.5±2.1%和CON大鼠的10.7±1.3% (P0.05)。 ⑶缺血/再灌注后60 min时,CIHH28和CIHH14+AEA大鼠冠脉流出液中的LDH分别为49.3±6.5和40.9±5.2,两者间无明显差异(P0.05),但明显低于CIHH14、AEA和CON大鼠的93.7±6.4、110.2±8.0和101.6±8.0(P0.05);心肌组织中SOD在CIHH28和CIHH14+AEA大鼠分别为229.7±6.7和239.3±6.2,两者间无明显差异(P0.05),但明显高于CIHH14、AEA和CON大鼠的160.2±6.7、170.7±7.3和181.9±4.4(P0.05);MDA在CIHH28和CIHH14+AEA大鼠分别为1.8±0.1和1.3±0.1,两者间无明显差异(P0.05),但明显低于CIHH14、AEA和CON大鼠的2.1±0.1、2.0±0.1和2.2±0.1(P0.05)。 ⑷CB1受体阻断剂AM251和CB2受体阻断剂AM630对CON大鼠的心功能无影响。AM630可明显抑制CIHH14+AEA大鼠心脏缺血后左心室功能的恢复,使LVDP、LVEDP和±LVdp/dtmax恢复率明显降低;同时冠脉流出液LDH升高,心肌组织SOD活性降低、MDA升高。而AM251无此作用。 结论:⑴28天CIHH处理具有明显的心脏保护作用,可促进大鼠缺血/再灌注后心功能的恢复,降低冠脉流出液中的LDH含量,增加心肌组织SOD活性和降低心肌组织MDA含量。 ⑵14天CIHH处理和低浓度AEA对心脏均无明显保护作用,但14天CIHH可增强AEA抗心肌缺血/再灌注损伤的心脏保护作用,促进缺血/再灌注后心功能的恢复,降低冠脉流出液中LDH含量,增加心肌组织SOD活性和降低心肌组织MDA含量。 ⑶CIHH对AEA的加强作用可被CB2受体阻断剂AM630所阻断。提示CIHH促进AEA的心脏保护作用可能由CB2受体所介导。
[Abstract]:Objective: many studies show that chronic intermittent hypobaric hypoxia (Chronic intermittent hypobaric hypoxia, CIHH) has obvious protective effect on heart, can enhance heart to ischemia, hypoxia tolerance, reduce ischemia / reperfusion on myocardial ischemia / reperfusion injury and promote the recovery of cardiac function after injection, and anti arrhythmia. Studies have reported that CIHH can change the reactivity of some drugs, thereby indirectly play a role in.Anandamide (AEA) is a kind of endogenous cannabinoid substances with anti myocardial ischemia, cardiac protective effects of anti arrhythmia. But I do not know the effect of CIHH on the cardioprotective effects of AEA. The purpose of this study was to use rats from ischemia body / heart reperfusion injury model, observe the effect of CIHH on the protective effect of AEA against myocardial ischemia / reperfusion, and to explore its mechanism.
Methods: male Sprague-Dawlay (SD) rats were randomly divided into 5 groups: intermittent hypoxia group (CIHH14) 14 days, 28 days of intermittent hypoxia group (CIHH28), anandamide group (AEA), 14 days of intermittent hypoxia AEA group (CIHH14+AEA) and control group (CON) in group.CIHH and CIHH+AEA rats were placed in a hypobaric chamber respectively, for 14 days, 28 days of simulated 5000 meters altitude (PB=404 mmHg, PO2=84 mmHg) hypoxia treatment, 6 hours a day.AEA and CON rats in hypoxia exposure, other treatments with the same group of intermittent hypoxia animal.
The rats were anesthetized and fixed, quickly open the chest, remove the heart, using Langendorff isolated heart perfusion preparation of myocardial ischemia / reperfusion model, namely the first stable perfusion for 30 min, 30 min perfusion (ischemia), and 60 min of reperfusion (reperfusion). The liquid capsule was inserted into the left ventricle, the indoor pressure the pressure transducer input recording system, were recorded from the heart of the basic state and ischemia / reperfusion and heart function in different time under the condition of change. Including the indexes of cardiac function: left ventricular developed pressure (left ventricular systolic pressure, LVDP), left at the end of Shi Shuzhang (left ventricular end diastolic pressure pressure, and LVEDP) the maximum change rate of left ventricular pressure (maximal positive and negative velocity of left ventrichlar pressure + LVdp/dtmax).
On the isolated rat heart, were treated with different drug intervention before ischemia. The heart of AEA and CIHH14+AEA rats, given 10 min before ischemia AEA (2 nM) of the pretreatment; the heart part of CIHH14+AEA rats, to AEA were given 10 min AEA CB2 receptor antagonist AM630 (10 nM) and CB1 receptor antagonist AM251 (10 nM) on the part of the pretreatment; CON isolated rat heart before ischemia were treated with 10 min AM630 (10 nM) and AM251 (10 nM) pretreatment.
During the experiment, take the monitoring time heart perfusion transudate (coronary flow), using the spectrophotometer to measure the lactate dehydrogenase method (lactate dehydrogenase, according to Lactate Dehydrogenase Kit LDH) content. After the end of the experiment, take heart, kept frozen in liquid nitrogen. By the method of xanthine oxidase method, determination of left ventricular myocardium superoxide dismutase (superoxide dismudase, SOD) activity, calculated by the thiobarbituric acid method malondialdehyde (malondialdehyde, MDA) content.
Results: the basic state, CIHH14, CIHH28, AEA, CIHH14+AEA and CON rats LVDP were 132.1 + 9.7132.0 + 12.8135.5 + 8.6131.6 + 8.5 and 132.2 + 11; LVEDP = 5.5 + 2.9,5.6 + 1.8,7.8 + 5.7,5.8 + 3.3 and 5.7 + 2.6; +LVdp/dtmax = 3606.4 + 97.13616.8 + 109.23610.3 + 116.83586.6 + 90.4 and 3617.3 + 97.9; -LVdp/dtmax = 2536.4 + 87.92612.0 + 46.42498.4 + 96.42480.4 + 63 and 2500.4 + 80.4, there were no significant differences between the parameters of heart function (P0.05).
鈶电己琛，

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