胸段硬膜外阻滞对心力衰竭兔血液动力学、神经内分泌和肺水通道蛋白AQP_4影响

The effects of thoracic epidural block on blood dynamics,neural endocrine and AQP_4 of rabbit with heart failure models

目的:探讨胸段硬膜外阻滞(TEB)对心力衰竭兔血液动力学、神经内分泌及肺组织水通道蛋白-4(AQP4)基因表达的影响。方法:将60只胸段硬膜外穿刺置管成功的兔随机分为3组(n=20);假手术组(S组),左冠状动脉前降支(LAD)仅置缝线,但不结扎,从硬膜外腔注入生理盐水0.5ml/kg,每天2次,连续4周;心力衰竭组(HF组),结扎LAD后第2天开始,从硬膜外腔注入生理盐水0.5ml/kg,每天2次,连续4周;TEB治疗组(TEB组),结扎LAD后第2天开始,从硬膜外腔注入0.1%罗哌卡因0.5ml/kg,每天2次,连续4周。术后4周经股动脉和颈总动脉直接插管测定血液动力学参数;用放免法测定血浆心钠素及内皮素浓度;逆转录一聚合酶链反应(RT-PCR)法半定量检测肺组织AQP4mRNA的表达。结果:心力衰竭组MAP、LVSP、±dp/dtmax明显下降,LVEDP、HR明显升高;血中内皮素和心钠素的浓度升高,肺AQP4mRNA的表达下降。经TEB治疗MAP、LVSP、±dp/dtmax有升高,LVEDP、HR显著降低;血中内皮素和心钠素的浓度降低,肺AQP4mRNA的表达增加。结论:胸段硬膜外阻滞可以改善心力衰竭兔血液动力学参数,降低血中ANP、ET-1的水平,并能部分纠正肺组织AQP4mRNA的异常表达。

Objective：To research the influence of thoracic epidural block on blood dynamics,neural endocrine hormone and the expression of AQP4 mRNA in the lung of rabbit with heart failure models. Methods：60 rabbits which were punctured and cannulated at the thoracic epidural cavity of T（5-6） were randomly divided into three groups （n=20）：sham operation group （group s）,in which the anterior descending branches of left coronary artery were threaded by suture but not tied;heart failure group （groupHF）,in which the anterior descending branches of left coronary artery were ligated,0.9%normal sodium 0.5ml/kg was injected to epidural space twice a bay for 4 weeks separately in group S and group HF. TEB group （group TEB）,in which 0.1%ropivacaine 0.5ml/kg was injected to epidural space twice a day for 4 weeks after the anterior descending branches of left coronary artery were ligated. After 4 weeks,blood dynamics were monitored directly by insertion through common carotid artery and femoral artery;the level of ANP and ET-1 were mensurated by radioimmunoassay（RIA）and the expression of AQP~ in the lung was quantified by reverse transcription-polymerase chain reaction （RT-PCR）. Results： （1） At 4 weeks after ligated LAD, LVEDP was increased significantly and MAP,LVSP、± dp/dt max were decreased significantly in group HF compared with group S. Therapy of TEB was significantly decreased LVEDP and were increased significantly MAP,LVSP、±dp/dt max. （2） Therapy of TEB decreased the level of ANP,ET-1 and increased the expression of AQP4mRNA of the rabbit with heart failure models. Conclusion：Thoracic epidural block have exert anti-heart failure effects by improving blood dynamics parameters, decreased secretion of ANP,ET-land increased the expression of AQP4mRNA in the lung of rabbits.