Jacob G, Nassar N, Hayam G, Ben-Haim S, Edoute Y, Better O S, Bomzon A
Department of Pharmacology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa.
Am J Physiol. 1993 Aug;265(2 Pt 1):G314-20. doi: 10.1152/ajpgi.1993.265.2.G314.
The function and role of the heart and the contribution of cardiac beta-adrenoceptors in the pathogenesis of circulatory failure in obstructive jaundice were studied in the 3-day bile duct-ligated (BDL) rat using three different techniques to measure cardiac function and beta-adrenoceptor activity, number, and affinity. The techniques were the pithed rat preparation, the isolated working heart preparation, and a competitive radioligand binding assay for beta-adrenoceptors. The results of these experiments were compared with those obtained in 3-day bile duct-manipulated (sham operated; SO) rats. Impaired indexes of basal cardiac contractility were observed in the BDL pithed rats and isolated working hearts. In these two preparations, responsiveness to norepinephrine and the beta-adrenoceptor agonists, isoproterenol and dobutamine, was unaffected by bile duct ligation. The affinity and number of cardiac beta-adrenoceptors in membranes from the hearts of SO and BDL rats were not significantly different from each other. These experiments have established for the first time that the 3-day BDL rat has a cardiac myopathy associated with intact responsiveness to beta-adrenoceptor agonists, a normal unchanged affinity and number of cardiac beta-adrenoceptors.
采用三种不同技术来测量心脏功能以及β-肾上腺素能受体活性、数量和亲和力，研究了阻塞性黄疸循环衰竭发病机制中心脏的功能和作用以及心脏β-肾上腺素能受体的贡献。这三种技术分别是脊髓横断大鼠制备、离体工作心脏制备以及β-肾上腺素能受体的竞争性放射性配体结合测定。将这些实验结果与3日胆管手术（假手术；SO）大鼠获得的结果进行比较。在胆管结扎的脊髓横断大鼠和离体工作心脏中观察到基础心脏收缩力指标受损。在这两种制备模型中，对去甲肾上腺素以及β-肾上腺素能受体激动剂异丙肾上腺素和多巴酚丁胺的反应性不受胆管结扎的影响。SO大鼠和胆管结扎大鼠心脏膜中心脏β-肾上腺素能受体的亲和力和数量彼此无显著差异。这些实验首次证实，3日胆管结扎大鼠存在一种心肌病，其对β-肾上腺素能受体激动剂反应性完整，心脏β-肾上腺素能受体亲和力和数量正常且未改变。
