吗啡胸段硬膜外给药对急性心肌缺血大鼠心肌β_1-肾上腺素能受体水平的影响

目的观察吗啡胸段硬膜外给药对急性心肌缺血大鼠心肌组织缺血区β1-肾上腺素能受体(β1AR)水平的影响。方法健康成年雄性SD大鼠36只,随机分为假手术组(S组)、单纯冠状动脉结扎组(CAO组)、冠状动脉结扎+吗啡硬膜外干预组(M组),各组在手术后计时3h取心脏。对缺血区心肌组织β1AR的表达分别采用免疫组织化学和蛋白质免疫印迹法进行检测。结果冠状动脉左前降支结扎后3h缺血区心肌组织β1AR蛋白水平较对照组明显升高,吗啡胸段硬膜外给药后其水平高于假手术组,但明显低于冠状动脉结扎组(P<0.05)。结论吗啡胸段硬膜外给药可在一定程度上抑制急性心肌缺血大鼠心肌组织β1AR的过度表达。

Effects of thoracic epidural morphine on expression of β1-adrenoceptors in the ischemic myocardium of the rat

Objective To investigate the effects of thoracic epidural morphine on expression of β1-adrenoceptors (β1AR) in rat ischemic myocardium following acute onset. Methods Thirty-six healthy adult male SD rats were randomly divided into sham group (group S), coronary artery occlusion group (group CAO), coronary artery occlusion plus epidural morphine group (group M), with 12 animals in each. After intrathecal catheterization, the left anterior descending branch of coronary artery was occluded for 3 h to create animal models with myocardial ischemia. Then the rats were sacrificed and harvested for hearts. We tested the levels of β1AR in rat ischemic myocardium by immunohistochemistry and Western blotting. Results Compared with group S, the level of β1AR expression was significantly increased after 3 h of ischemia in group CAO. With thoracic epidural morphine, the expression of β1AR was significantly lower than in group S, although higher than in group CAO (P<0.05). Conclusion To a certain extent, thoracic epidural infusion of morphine can be inhibitory against the excessive expression of myocardial β1AR induced by ischemia.