心得安对实验性心肌梗塞大鼠心肌膜β受体的影响

EFFECTS OF PROPRANOLOL ON B-ADRENERGIC RECEPTOR OF EXPERIMENTAL ACUTE MYOCARDIAL INFARCTION IN THE RATS

本文采用受体放射自显影术,以银粒数的分布与数量变化作为观察指标,对β受体阻滞剂心得安治疗实验性急性心肌梗塞(AMI)大鼠的心肌膜β肾上腺素能受体(β受体)的影响进行研究.左冠状动脉前降支(LAD)结扎后一周引起心肌梗塞区内[3H]DHA结合位点数显著降低,在非梗塞区亦降低.结扎LAD应用心得安(100ug/kg)治疗一周后梗塞区[3H]DHA结合位点数明显回升,而非梗塞区则进一步降低.引人注目的是,心得安治疗后,[3H]DHA结合位点数在梗塞区/非梗塞区的比值由LAD结扎时的0.24上升为0.87,接近于假手术对照组的0.97.结果证明,心得安是直接作用于心脏的β受体,可能还通过调整了梗塞区与非梗塞区β受体的平衡,改善了心室的顺应性和提高了梗塞心脏的收缩协同作用.从而对AMI的心脏起到保护和治疗作用.

By using receptor autoradiography to observe the distribution and density, we studied the effects of β-blocker, propranolol on β-adrenergic receptor of experimental acute myocardial infarction (AMI). After one week of proximate left anterior descend (LAD) coronary artery ligation, (3H) DHA binding sites were markedly decreased in the infarct region and decreased in the non-infaret region as well. With the propranolol treatment (100 ug/ kg), the (3H) DHA binding sites were obviously increased in the infarct region, but further decreased in the non-infarct region. More interesting was that, the ratio of (3H) DHA binding sites of the infarct region and non-infarct region was from 0. 24 of LAD ligation to 0. 87 of propranolol treatment, close to 0. 97 of shamoperation control group. The results indicated that the propranolol acted directly on myocardial β-adrenergic through the receptor regulation of the balance of β-receptor between the infarct region and non-infarct region, and improvement of the myocardial consonation and constraction synergy. Thus it could protect and cure the heart affected by acute myocardial infarct.