目的　探讨心肌顿抑 (MS)时局部组织一氧化氮 (NO)含量的变化。方法　开胸阻断犬左前降支 (LAD)15min ,实验组分别再灌注NO合成前体L 精氨酸 (L Arg)、供体Sin 1、一氧化氮合酶 (NOS)抑制剂L NAME ,通过将NO检测电极与左室前壁MS组织流出血液密切接触的直接测定法及用Greiss法检测冠状窦血样的间接测定法 ,观察MS组织NO含量的变化。结果　MS组织NO含量降低 ,再灌注L Arg及Sin 1可明显增加局部MS组织NO的含量。结论　NO合成减少参与了MS的发生过程 ,外源性NO补充可能对MS的防治产生有益的作用。 Objective To investigate the changes of nitric oxide (NO) contents in local tissues during myocardial stunning. Methods The left anterior descending (LAD) of canine was blocked by thoracotomy for 15 minutes. The experimental group was reperfused with L Arg, Ligand Sin 1, NOS inhibitor L NAME, The changes of NO content in MS tissue were observed by direct determination of the NO detection electrode in close contact with outflow of blood from the anterior wall of the left ventricular wall and indirect measurement of coronary sinus blood samples by the Greiss method. Results The NO content in MS tissue decreased. Reperfusion of L Arg and Sin 1 significantly increased NO content in MS tissue. Conclusion NO synthesis is involved in the pathogenesis of MS. Exogenous NO supplementation may have a beneficial effect on the prevention and treatment of MS.