α肾上腺受体在调节血管张力和反应性方面,可能行使重要的作用。血管α肾上腺受体的药物学特性,过去是通过血管的收缩,间接反应的,因此,对血管α肾上腺受体的生物化学特性及其调节作用仍不太清楚。近年来,由于放射性配基结合技术的迅速发展,改进了肾上腺受体的研究。已采用的氚标记α配基有[~3H]dihydroergocryptine、[~3H]yohimbine、[~3H]WB 4101。1981年Colucci等用放射性配基成功地测定了大鼠肠系膜动脉的α受体,发现它是α_1亚型。但由于氚标记的放射性配基相对特异性小、比放射性低、测定动脉平滑肌受体时需要大量的血管组织来制备膜受体,这对于一些小型实验动物,存在不少困难。最近,Tsujimoto等报道了一种新型的、高特异性的、有效的、同位素碘标记的α配基——[~(125)I]BE 2254。药理学实验说明,BE 2254对α_1受体有优先的抑制作用,用~(125)I标记的化合物,更增加了对α_1肾上腺受体 Alpha adrenoceptors may play an important role in regulating vascular tone and reactivity. The pharmacological properties of vascular alpha adrenal receptors, which used to act indirectly through the vasoconstriction, are not yet clear on the biochemical properties of vascular alpha adrenoceptors and their regulatory roles. In recent years, due to the rapid development of radioligand binding technology, adrenal receptors have been improved. Tritium labeled alpha ligands have been used as [~ 3H] dihydroergocryptine, [~ 3H] yohimbine, [~ 3H] WB 4101. Colucci et al. Successfully measured the α receptor of the rat mesenteric artery using radioligands in 1981 and found that It is alpha 1 subtype. However, due to the relative specificity of tritium-labeled radioligands is relatively low than radioactive, a large number of vascular tissue is required for the preparation of membrane receptors for the determination of arterial smooth muscle receptors, which is difficult for some small experimental animals. Recently, Tsujimoto et al. Reported a novel, highly specific and potent isotope-labeled α-ligand [- (125) I] BE 2254. Pharmacological experiments show that, BE 2254 has a preferential inhibition of α 1 receptor, with 125 I labeled compounds, but also increased the α 1 adrenoceptors