Dahm P L, Bodelsson M, Törnebrandt K, Muddle J R, Sykes R M, Yacoub M, Dashwood M R
Department of Anaesthesiology, University Hospital of Lund, Sweden.
Cardiovasc Res. 1996 May;31(5):800-6. doi: 10.1016/0008-6363(96)00029-6.
5-Hydroxytryptamine (5-HT) has a wide range of vascular effects mediated via specific receptors and it has been suggested to be a mediator in ischemic heart disease. The aim of the present study was to localise the 5-HT receptors within the vessel wall.
Epicardial coronary arteries obtained from patients undergoing cardiac transplantation, internal mammary arteries from heart donors and saphenous veins from patients undergoing coronary bypass surgery, were sectioned and incubated with [3H]-5-HT for in vitro receptor autoradiography.
Microscopic analysis of high resolution autoradiographic images revealed a similar pattern of [3H]-5-HT binding in epicardial coronary and internal mammary artery, where it predominated in the lamina muscularis. In the saphenous vein, binding increased towards the adventitia which showed dense, displaceable binding to the vasa vasorum as well as to nerve-like structures, from which binding was only partially displaced. Computer-assisted densitometric analysis of low resolution autoradiographs revealed a high degree of specific binding to all vessels examined.
The distribution of the [3H]-5-HT binding is different in the saphenous vein compared to epicardial coronary and internal mammary artery. The dense binding to vasa vasorum in the saphenous vein suggests a role for 5-HT in closure of these nutrient vessels, which could contribute to the formation of atherosclerotic changes in saphenous vein grafts.
5-羟色胺（5-HT）通过特定受体介导产生广泛的血管效应，有人提出它是缺血性心脏病的一种介质。本研究的目的是在血管壁内定位5-HT受体。
取自心脏移植患者的心外膜冠状动脉、心脏供体的乳内动脉以及冠状动脉搭桥手术患者的大隐静脉，进行切片并用[3H]-5-HT孵育，用于体外受体放射自显影。
对高分辨率放射自显影图像的显微镜分析显示，心外膜冠状动脉和乳内动脉中[3H]-5-HT结合模式相似，主要集中在肌层。在大隐静脉中，结合向外膜增加，外膜显示出对血管滋养管以及神经样结构有密集的、可置换的结合，其中只有部分结合可被置换。对低分辨率放射自显影片的计算机辅助密度分析显示，在所检查的所有血管中都有高度的特异性结合。
与心外膜冠状动脉和乳内动脉相比，大隐静脉中[3H]-5-HT结合的分布有所不同。大隐静脉中对血管滋养管的密集结合表明5-HT在这些营养血管的闭合中起作用，这可能有助于大隐静脉移植物中动脉粥样硬化病变的形成。
