乙酰胆碱洗脱后所致心脏作用的反跳及其机制研究

发布时间：2018-05-01 22:06

本文选题：乙酰胆碱 + 洗脱　；参考：《石河子大学》2008年硕士论文

【摘要】： 目的:研究乙酰胆碱(acetylcholine, ACh)灌注并迅速洗脱后所致离体兔心正性肌力作用的规律及其可能机制,探讨ACh灌注与洗脱对离体家兔右心房复极时限及跨壁复极离散度(transmural dispersion of repolarization, TDR)的影响。方法:采用Langendorff离体心脏灌流技术,观察对照组与实验组共28例在给予ACh并洗脱后离体兔心的心肌收缩力变化;采用单相动作电位(MAP)记录技术,同步且同部位记录9例家兔右房心外膜心肌、中层心肌和心内膜心肌MAP,测量并计算ACh(1×10-5 mol/L,0.3 ml/kg)灌注及洗脱后,心房肌MAP复极达50%与90%的时间(MAPD50与MAPD90)及其TDR。结果:10-8~10-3 mol/L浓度的ACh灌注并立即洗脱后所致心肌收缩力的最大反跳率分别为2.22%±1.70%、6.71%±3.40%、9.18%±3.54%、14.16%±3.27%、4.37%±5.86%、1.03%±6.86%;肾上腺素组的最大反跳率为29.25%±5.83%,普萘洛尔组最大反跳率为5.15%±4.45%,二者与对照组同浓度ACh (1×10-5 mol/L)相比,均有显著统计学差异(P0.05, n=7);维拉帕米组持续800 s未出现反跳现象。ACh灌注时,三层心房肌的MAPD50、MAPD90及MAPD90-50值较ACh灌注前延长(P0.05,给药后30±5 s; n=9),TDR50、TDR90和TDR90-50值较给药前增加(P0.05,给药后30±5 s; n=9);在ACh洗脱后,三层右房心肌MAPD50、MAPD90、MAPD90-50及其TDR值的变化,较灌注ACh前无显著差异(P0.05,给药后100±5 s; n=9)。结论:在离体兔心,我们可以观察到ACh灌注并迅速洗脱后出现的负性与正性肌力作用;ACh洗脱后所致的正性肌力作用与心肌Ca2+通道、β受体的活性有关;ACh洗脱后与高浓度ACh时引起正性肌力作用的机制可能存在不同;ACh灌注时与洗脱后在右房复极方面存在明显不同的电生理变化,它们所致心律失常的机制有必要从多角度进行进一步研究。
[Abstract]:Objective: To study the regularities and possible mechanisms of positive inotropic action of the isolated rabbit heart after acetylcholine (ACh) perfusion and rapid elution, and to explore the effect of ACh perfusion and elution on the repolarization time limit of right atrium and transmural dispersion of repolarization (TDR) in the right atrium of rabbit in vitro.
Methods: Langendorff isolated heart perfusion technique was used to observe the changes of myocardial contractility in 28 cases of the isolated rabbit heart after ACh and elution in the control group and the experimental group. The single phase action potential (MAP) recording technique was used to record the right atrial epicardial myocardium in 9 rabbits, the middle myocardium and the cardiac endomyocardial MAP were recorded simultaneously and in the same site. The ACh (1 x) was measured and calculated. After 10-5 mol/L, 0.3 ml/kg perfusion and elution, the MAP repolarization of atrial muscle reached 50% and 90% (MAPD50 and MAPD90) and TDR. respectively.
Results: the maximum rebound rate of myocardial contractility induced by ACh perfusion and immediate elution of 10-8~10-3 mol/L was 2.22% + 1.70%, 6.71% + 3.40%, 9.18% + 3.54%, 14.16% + 3.27%, 4.37% + 5.86%, 1.03% + 6.86%, and the maximum rebound rate of epinephrine group was 29.25% + 5.83%, and the maximum rebound rate of propranolol group was Compared with the same concentration of ACh (1 x 10-5 mol/L), there were significant statistical differences (P0.05, n=7), while the MAPD50, MAPD90 and MAPD90-50 values of three layers of atrial muscle were prolonged (P0.05, 30 + 5 s,) in the Vera Pammy group sustained 800 s without the phenomenon of reverse jump.ACh perfusion (30 + 5 after administration). (n=9); after ACh elution, the changes of MAPD50, MAPD90, MAPD90-50 and TDR values in the three layers of right atrial myocardium were not significantly different from those before perfusion ACh (P0.05, 100 + 5 s after administration; n=9).
Conclusion: in the isolated rabbit heart, we can observe the negative and positive inotropic action after ACh perfusion and rapid elution. The positive inotropic action after ACh elution is related to the myocardial Ca2+ channel, the activity of beta receptor, and the mechanism of positive inotropic action may be different from the high concentration ACh after ACh elution; ACh perfusion and elution after elution. There are obvious electrophysiological changes in the repolarization of right atrium. The mechanism of arrhythmia induced by them is necessary to further study from multiple angles.

【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R33

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