Zaini A, Pearce P, Funder J W
Clin Exp Pharmacol Physiol. 1987 Jan;14(1):39-45. doi: 10.1111/j.1440-1681.1987.tb00955.x.
The use of sodium molybdate as a stabilizing agent, and a RU26988 to exclude [3H]aldosterone from Type II glucocorticoid receptors, has enabled us to characterize high affinity Type I aldosterone binding sites in rat liver cytosol. In liver cytosols from male rats aldosterone bound with an affinity (Kd-22 degrees C) of 0.6 nmol/l (range 0.3-0.8 nmol/l), and Nmax 1.7 fm/mg protein (s.e.m. = 0.4); specificity of binding was similar to that for Type I sites in classical aldosterone target tissues (aldosterone greater than or equal to corticosterone greater than dexamethasone). Hepatic Type I receptor levels were relatively constant in both male and female rats aged 30-120 days, with levels significantly higher in females. Parallel studies on hepatoma H4 cells showed levels of Type I sites similar to those in normal liver, suggesting a general distribution of such sites throughout liver parenchyma, rather than a concentration in a specific cell type. The function of such Type I sites, and whether or not they are aldosterone-selective in vivo and can thus act as mineralocorticoid receptors, remains to be determined.
使用钼酸钠作为稳定剂，并用RU26988将[3H]醛固酮排除在II型糖皮质激素受体之外，这使我们能够对大鼠肝细胞溶胶中的高亲和力I型醛固酮结合位点进行表征。在雄性大鼠的肝细胞溶胶中，醛固酮的结合亲和力（22℃时的Kd）为0.6 nmol/l（范围为0.3 - 0.8 nmol/l），Nmax为1.7 fm/mg蛋白质（标准误 = 0.4）；结合特异性与经典醛固酮靶组织中的I型位点相似（醛固酮≥皮质酮＞地塞米松）。在30 - 120日龄的雄性和雌性大鼠中，肝脏I型受体水平相对恒定，雌性大鼠的水平显著更高。对肝癌H4细胞的平行研究表明，I型位点的水平与正常肝脏中的相似，这表明这些位点在整个肝实质中普遍分布，而不是集中在特定细胞类型中。这种I型位点的功能，以及它们在体内是否对醛固酮具有选择性，从而能否作为盐皮质激素受体，仍有待确定。
