Duc I, Botella J, Delansorne R, Paris J
Laboratoire Theramex, Principauté de Monaco, Service de Biologie Cellulaire.
Steroids. 1991 Jun;56(6):325-8. doi: 10.1016/0039-128x(91)90055-z.
The binding characteristics of the progestin 17 alpha-acetoxy-6-methyl-19-[3H]norpregna-4,6-diene-3,20-dione, nomegestrol acetate ([3H]NOM-Ac) to progesterone receptors (PgRs) of uterus were determined in the rat. Scatchard plot analysis of the equilibrium binding data showed that [3H]NOM-Ac binds to uterine PgR with a Kd of 5.44 +/- 1.27 nM and a Bmax of 1.51 +/- 0.11 pmol/mg protein. Analysis of dissociation kinetics showed that [3H]NOM-Ac dissociates slowly from the PgR, k - 1 = 4.9 +/- 0.5 10(-5) s-1. Competition experiments against [3H]NOM-Ac showed the specificity of the binding with a sequence in relative affinity as follows: ORG 2058 greater than P greater than NOM-Ac greater than medroxyprogesterone acetate greater than megestrol acetate greater than cyproterone acetone greater than NOM.
在大鼠中测定了孕激素17α-乙酰氧基-6-甲基-19-[³H]去甲孕甾-4,6-二烯-3,20-二酮，即醋酸诺美孕酮（[³H]NOM-Ac）与子宫孕激素受体（PgRs）的结合特性。对平衡结合数据进行Scatchard作图分析表明，[³H]NOM-Ac与子宫PgR结合的解离常数（Kd）为5.44±1.27 nM，最大结合容量（Bmax）为1.51±0.11 pmol/mg蛋白质。解离动力学分析表明，[³H]NOM-Ac从PgR上缓慢解离，解离速率常数（k - 1）为4.9±0.5×10⁻⁵ s⁻¹。与[³H]NOM-Ac进行的竞争实验表明了结合的特异性，相对亲和力顺序如下：ORG 2058＞孕酮＞醋酸诺美孕酮＞醋酸甲羟孕酮＞醋酸甲地孕酮＞醋酸环丙孕酮＞诺美孕酮。
