Ivanisevic M, Behrens O, Helmer H, Demarest K, Fuchs A R
Department of Obstetrics and Gynecology, Cornell University Medical College, New York, NY 10021.
Am J Obstet Gynecol. 1989 Dec;161(6 Pt 1):1637-43. doi: 10.1016/0002-9378(89)90941-1.
Saturation analysis and competition experiments were performed to identify and characterize [3H]arginine vasopressin binding to human myometrium and decidua in late pregnancy. [3H]Arginine vasopressin bound with affinity similar to that of [3H]oxytocin to both tissues (dissociation constant 1 to 2 nmol/L). The concentration of [3H]arginine vasopressin binding sites was high, particularly in decidua, but in all instances was about 50% to 60% of [3H]oxytocin binding. Analogs with selective oxytocic potency (4-threonine oxytocin, isotocin) had high affinity to both [3H]arginine vasopressin and [3H]oxytocin binding sites, as did analogs with both oxytocic and vasopressor activity (vasotocin). Analogs with selective antidiuretic activity (1-deamino-8-D-arginine vasopressin) showed drastically reduced affinity to [3H]oxytocin binding sites and relatively low but significantly higher affinity to [3H]arginine vasopressin binding sites. A new oxytocin antagonist (RW22164 or [1-deamino-2D-tyrosine-(O-ethyl)-4-threonine-8-ornithine]oxytocin) competitively bound to both binding sites. Its affinity to [3H]oxytocin binding sites was greater than to [3H]arginine vasopressin binding sites whereas the relative affinities of a predominantly vasopressor antagonist [Manning compound) were reversed, suggesting the presence of distinct receptors for oxytocin and arginine vasopressin in pregnant human myometrium and decidua.
进行了饱和分析和竞争实验，以鉴定和表征妊娠晚期[3H]精氨酸加压素与人子宫肌层和蜕膜的结合情况。[3H]精氨酸加压素与两种组织的结合亲和力与[3H]催产素相似（解离常数为1至2 nmol/L）。[3H]精氨酸加压素结合位点的浓度很高，尤其是在蜕膜中，但在所有情况下约为[3H]催产素结合位点的50%至60%。具有选择性催产效力的类似物（4-苏氨酸催产素、异催产素）对[3H]精氨酸加压素和[3H]催产素结合位点均具有高亲和力，同时具有催产和升压活性的类似物（加压催产素）也是如此。具有选择性抗利尿作用的类似物（1-脱氨基-8-D-精氨酸加压素）对[3H]催产素结合位点的亲和力大幅降低，而对[3H]精氨酸加压素结合位点的亲和力相对较低但显著更高。一种新的催产素拮抗剂（RW22164或[1-脱氨基-2D-酪氨酸-(O-乙基)-4-苏氨酸-8-鸟氨酸]催产素）竞争性地结合到两个结合位点。它对[3H]催产素结合位点的亲和力大于对[3H]精氨酸加压素结合位点的亲和力，而一种主要的升压拮抗剂（曼宁化合物）的相对亲和力则相反，这表明在妊娠人类子宫肌层和蜕膜中存在不同的催产素和精氨酸加压素受体。
