Ishii K, Kano T, Ando J
Jpn J Pharmacol. 1986 May;41(1):47-54. doi: 10.1254/jjp.41.47.
Properties of [3H]nitrendipine binding, high K+- and Ca++-induced contractions and the inhibition of high K+-induced contractions by verapamil were investigated in the uterine preparations isolated from rats treated with estrogen or progesterone or both. In [3H]nitrendipine binding experiments using crude membrane fractions, treatment with estrogen alone or estrogen+progesterone significantly lowered the KD; There was very little change in the Bmax. In the Ca++-depleted, high K+-containing medium, only the progesterone-, and estrogen----progesterone-treated uteri produced contractions. The estrogen-, estrogen----progesterone-, and estrogen+progesterone-treated uteri showed decreases in concentrations of Ca++ required for the maximal contractions. In the estrogen- and estrogen+progesterone-treated uteri, the dose-response curves by verapamil were shifted to the left in a parallel manner. These findings suggest that estrogen appeared to increase the affinity of calcium channels and increase transmembrane influx of Ca++, leading to enhancement of contractions, whereas progesterone might increase the Ca++ storage in the intracellular sites.
在从接受雌激素或孕激素或两者治疗的大鼠分离出的子宫制剂中，研究了[3H]尼群地平结合特性、高钾和钙离子诱导的收缩以及维拉帕米对高钾诱导收缩的抑制作用。在使用粗膜组分的[3H]尼群地平结合实验中，单独使用雌激素或雌激素加孕激素处理显著降低了解离常数（KD）；最大结合容量（Bmax）变化很小。在钙离子耗尽、含高钾的培养基中，只有孕激素处理以及雌激素加孕激素处理的子宫产生收缩。雌激素处理、雌激素加孕激素处理以及雌激素加孕激素处理的子宫显示最大收缩所需的钙离子浓度降低。在雌激素处理和雌激素加孕激素处理的子宫中，维拉帕米的剂量反应曲线以平行方式向左移动。这些发现表明，雌激素似乎增加了钙通道的亲和力并增加了钙离子的跨膜内流，导致收缩增强，而孕激素可能增加细胞内位点的钙离子储存。
