体外循环（CPB）是心脏外科手术的基石。随着心脏外科手术水平的不断提高，患者病情越来越复杂，随之而来的是CPB时间延长。因此需不断提高灌注技术，同时也需进一步了解CPB病理生理改变以更好的保护脏器。已有报道体外循环可导致下丘脑发生改变，而下丘脑是心血管系统的高级控制中枢。因此，体外循环过程中心肌损伤，不仅来源于外科手术的直接作用，还可能来源于下丘脑的改变，但具体损伤机制尚不明确。项目组在前期研究中发现体外循环过程中下丘脑sigma-1受体表达下降，心肌交感神经活性增强。而sigma-1受体可调控交感神经活性，具有心肌保护作用。因此拟通过下丘脑微注射技术，使下丘脑sigma-1受体表达改变，观察大鼠体外循环过程中，心肌损害和交感神经活性的相关指标以及脑区核团神经递质的改变， 探讨下丘脑sigma-1受体对体外循环中心肌的影响，为临床指导用药提供新思路。

Cardiopulmonary bypass (CPB)is essential for heart operation. The condition is growing complicated as the development of surgery followed by the time of CPB is extended. So it is necessary to explore more pathophysiological changes to protect organs against injury. CPB causes changes in hypothalamus which is the center of cardiovascular system. So, the source of damage is not only the direct effect but also the changes of hypothalamus during CPB. Previous study indicated that the expression of sigma-1 receptor in hypothalamus was decreased and the activity of sympathetic nerve in heart was increased. It was found that sigma-1 receptor contributed to reducing activity of sympathetic nerve and protecting heart against injury. So we explore the effect of sigma-1 receptor in hypothalamus on heart during CPB by observing items of myocardial damage and activity of sympathetic nerve and changes of neurotransmitter.