Kornel L, Kanamarlapudi N, Travers T, Taff D J, Patel N, Chen C, Baum R M, Raynor W J
J Steroid Biochem. 1982 Feb;16(2):245-64. doi: 10.1016/0022-4731(82)90173-x.
High affinity, specific binding-sites to mineralocorticoids and glucocorticoids, with characteristics of steroid receptors, have been found in rabbit aorta cytosol. Binding parameters (dissociation constants and number of binding sites per mg of cytosol protein) were determined from Scatchard plots, after statistical treatment of the data with the aid of a computer program, for the following tritiated steroids: 11-desoxycorticosterone (DOC), aldosterone (Aldo), progesterone (Prog), corticosterone (BK), cortisol (FK) and dexamethasone (Dex). The specificity of binding was then examined by means of steroid competition studies. The results of these experiments indicate that three different types of high-affinity binding sites to adrenal steroids are present in aorta cytosol: Type A, with the highest affinity for DOC; Type B, with the highest affinity for FK; Type C, with the highest affinity for Dex. In accordance with the relative competitive potencies of various steroids for these binding sites, Type A is designated as the "arterial mineralocorticoid binder", clearly differing in its binding characteristics from the cytoplasmic mineralocorticoid binders in known target tissues to these steroids (e.g. the renal receptor), while Type C is designated as the "arterial glucocorticoid binder", closely resembling the classical glucocorticoid receptor in known target tissues to glucocorticoids. Type B exhibited some of the binding characteristics of transcortin and may represent a modified, intracellular transcortin. While Types B and C are present also in the cytosol of inferior vena cava. Type A was only in the aorta. The role of these binders is not known at present. Arguments are presented in favor of a hypothesis that the Type A (mineralocorticoid) binder represents an arterial wall; and that, under certain conditions, this action leads to an increased contractility of arterial and arteriolar smooth muscles, increased peripheral resistance and hypertension.
在兔主动脉胞质溶胶中发现了对盐皮质激素和糖皮质激素具有高亲和力的特异性结合位点，这些位点具有类固醇受体的特征。在用计算机程序对数据进行统计处理后，根据Scatchard图确定了以下氚标记类固醇的结合参数（解离常数和每毫克胞质溶胶蛋白的结合位点数）：11-脱氧皮质酮（DOC）、醛固酮（Aldo）、孕酮（Prog）、皮质酮（BK）、皮质醇（FK）和地塞米松（Dex）。然后通过类固醇竞争研究来检验结合的特异性。这些实验结果表明，主动脉胞质溶胶中存在三种不同类型的对肾上腺类固醇具有高亲和力的结合位点：A型，对DOC亲和力最高；B型，对FK亲和力最高；C型，对Dex亲和力最高。根据各种类固醇对这些结合位点的相对竞争能力，A型被指定为“动脉盐皮质激素结合蛋白”，其结合特性与已知靶组织中这些类固醇的细胞质盐皮质激素结合蛋白（如肾受体）明显不同，而C型被指定为“动脉糖皮质激素结合蛋白”，与已知糖皮质激素靶组织中的经典糖皮质激素受体非常相似。B型表现出一些皮质素转运蛋白的结合特性，可能代表一种修饰的细胞内皮质素转运蛋白。虽然B型和C型也存在于下腔静脉的胞质溶胶中，但A型仅存在于主动脉中。目前尚不清楚这些结合蛋白的作用。有人提出论据支持这样一种假说，即A型（盐皮质激素）结合蛋白代表动脉壁；并且在某些情况下，这种作用会导致动脉和小动脉平滑肌收缩力增加、外周阻力增加和高血压。
