Rao CH V, Griffin L P, Carman F R
Am J Obstet Gynecol. 1977 May 15;128(2):146-53. doi: 10.1016/0002-9378(77)90678-0.
Binding of 125I-human choriogonadotropin (hCG) to homogenates of corpora lutea of the menstrual cycle and pregnancy was examined. While corpora lutea of the menstrual cycle bound 125I-hCG, most of the corpora lutea of pregnancy from six to 34 weeks' gestation bound little or none of the added 125 I-hCG. Further exploration into various possibilities for the above findings led to the conclusion that these corpora lutea either contain very few gonadotropin receptors or lack them altogether. The selected properties of gonadotropin receptors in corpora lutea of the cycle were studied. The apparent dissociation constant for binding was about the same (2.6 to 3.8 x 10-10M) in all but one corpus luteum. In this one sample the constant was three- to five-fold higher (1.3 x 10-9M). The binding was quite rapid and reversible, and it exhibited dependence on the amount of 125I-hCG, homogenate protein, pH of the incubation media, and duration of incubation. hCG and human lutropin (hLH') competed for 125I-hCG binding, but hCG subunits (alpha and beta), human follitropin, and ovine prolactin did not. Although hCG and hLH were parallel in inhibiting 125I-hCG binding, hLH was found to be relatively less effective. The studies with various enzymes revealed that gonadotropin receptors are protein in nature.
研究了125I-人绒毛膜促性腺激素（hCG）与月经周期及孕期黄体匀浆的结合情况。月经周期的黄体可结合125I-hCG，而妊娠6至34周的大多数黄体对添加的125I-hCG结合很少或根本不结合。对上述发现的各种可能性进行进一步探究后得出结论，即这些黄体要么含有极少的促性腺激素受体，要么完全缺乏促性腺激素受体。研究了周期黄体中促性腺激素受体的选定特性。除一个黄体样本外，所有黄体样本中结合的表观解离常数大致相同（2.6至3.8×10-10M）。在这个样本中，该常数高出三至五倍（1.3×10-9M）。结合相当迅速且可逆，并且它表现出对125I-hCG量、匀浆蛋白、孵育介质的pH值以及孵育持续时间的依赖性。hCG和人促黄体生成素（hLH'）竞争125I-hCG的结合，但hCG亚基（α和β）、人促卵泡生成素和绵羊催乳素则不竞争。尽管hCG和hLH在抑制125I-hCG结合方面表现相似，但发现hLH的效果相对较差。对各种酶的研究表明，促性腺激素受体本质上是蛋白质。
