Brunvand H, Grong K
Department of Surgery, University of Bergen, Haukeland University Hospital, Norway.
J Pharmacol Exp Ther. 1997 Jul;282(1):363-8.
The purpose of our study was to investigate whether loss of myocardial contraction immediately after coronary occlusion was nonuniform, and if pretreatment with carvedilol, a vasodilating nonselective beta-adrenoceptor antagonist, could retard loss of contraction after coronary artery occlusion. Feline hearts were subjected to acute regional ischemia by total occlusion of the left anterior descending coronary artery. The animals were either treated with vehicle (control group) or with carvedilol 1 mg/kg i.v. before left anterior descending coronary artery occlusion (n = 9 in each group). Regional contraction in the left anterior descending coronary artery perfused region of the heart was studied by cross-oriented sonomicrometry. In control animals, circumferential (subepicardial) contraction ceased after 10 sec, whereas longitudinal (subendocardial) contraction ceased immediately after left anterior descending coronary artery occlusion. Loss of contraction in animals treated with carvedilol was significantly slower compared to controls. Circumferential contraction ceased between 30 sec and 1 min, whereas longitudinal contraction ceased after 20 sec. In conclusion, loss of contraction during the first seconds after coronary occlusion was nonuniform, with most rapid dysfunction in the subendocardium. Pretreatment with carvedilol retarded loss of contraction in both axes.
我们研究的目的是调查冠状动脉闭塞后心肌收缩力的丧失是否不均匀，以及血管舒张性非选择性β-肾上腺素能受体拮抗剂卡维地洛预处理是否能延缓冠状动脉闭塞后收缩力的丧失。通过完全闭塞左冠状动脉前降支使猫心脏遭受急性局部缺血。在左冠状动脉前降支闭塞前，动物分别接受赋形剂处理（对照组）或静脉注射1mg/kg卡维地洛（每组n = 9）。通过交叉定向超声心动图测量研究心脏左冠状动脉前降支灌注区域的局部收缩。在对照动物中，圆周（心外膜下）收缩在10秒后停止，而纵向（心内膜下）收缩在左冠状动脉前降支闭塞后立即停止。与对照组相比，接受卡维地洛治疗的动物收缩力丧失明显较慢。圆周收缩在30秒至1分钟之间停止，而纵向收缩在20秒后停止。总之，冠状动脉闭塞后的最初几秒内收缩力丧失不均匀，心内膜下功能障碍最为迅速。卡维地洛预处理延缓了两个轴向上收缩力的丧失。
