Tsukahara T, Kassell N F, Hongo K, Vollmer D G, Ogawa H
Department of Neurological Surgery, University of Virginia School of Medicine, Charlottesville.
J Cereb Blood Flow Metab. 1989 Dec;9(6):748-53. doi: 10.1038/jcbfm.1989.107.
To characterize the muscarinic cholinergic receptors on the endothelium of human cerebral arteries, isometric tension measurement and receptor autoradiographic studies were performed. Acetylcholine (ACh) induced dose-dependent relaxation of human cerebral arteries precontracted by 10(-5) M serotonin, with an EC50 of 1.9 +/- 0.6 X 10(-6) M (n = 7). The relaxation was abolished by 10(-5) M hemoglobin. Autoradiography, using the muscarinic antagonist [3H]propylbenzilycholine mustard, demonstrated the high density of muscarinic cholinergic receptors on the endothelial cells of human cerebral arteries, especially on the luminal surface of the endothelium. These findings suggest that ACh-induced relaxation mediated by muscarinic cholinergic receptors on the endothelium has a physiological function in human cerebral arteries.
为了表征人脑中动脉内皮上的毒蕈碱型胆碱能受体，进行了等长张力测量和受体放射自显影研究。乙酰胆碱（ACh）可诱导由10^(-5) M 5-羟色胺预收缩的人脑中动脉产生剂量依赖性舒张，其半数有效浓度（EC50）为1.9±0.6×10^(-6) M（n = 7）。10^(-5) M血红蛋白可消除这种舒张作用。使用毒蕈碱拮抗剂[3H]丙基苯甲酰胆碱氮芥进行的放射自显影显示，人脑中动脉内皮细胞上存在高密度的毒蕈碱型胆碱能受体，尤其是在内皮的管腔表面。这些发现表明，由内皮上的毒蕈碱型胆碱能受体介导的ACh诱导的舒张在人脑中动脉中具有生理功能。
