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 T5～6 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 AQP4 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-1and increased the expression of AQP4mRNA in the lung of rabbits.