Rolland R, Hammond J M
Endocr Res Commun. 1975;2(3):281-98. doi: 10.3109/07435807509053855.
Porcine granulosa cells and subcellular fractions from these cells have been shown to have a specific receptor for ovine prolactin (OPRL). Ovine growth hormone demonstrated 7% of the potency of OPRL in displacing 125I-OPRL from its binding site; FSH, TSH, LH, insulin and ACTH showed negligible cross-reactivity. Scatchard analysis of the displacement curves suggested that 125I-OPRL has a high affinity for its receptor with a dissociation constant (Kd) for the granulosa cell-receptor of 7.4-7.7 times 10(-10) M with no change as the follicle enlarges. In contrast, the specific binding of prolactin decreased markedly with maturation of the follicles with an apparent decrease in binding sites/cell from 555 in small follicles to 300 in large (preovulatory) follicles. The demonstrated Kd's were within the range of prolactin concentrations easily attained in vivo and were in good agreement with values obtained in our laboratory and elsewhere for the prolactin receptor from mammary gland and other tissues. Consequently, these studies may provide a basis for a better understanding of the role of prolactin in ovarian function.
猪颗粒细胞及其亚细胞组分已被证明具有绵羊催乳素（OPRL）的特异性受体。绵羊生长激素在将125I-OPRL从其结合位点置换出来方面表现出OPRL效力的7%；促卵泡激素（FSH）、促甲状腺激素（TSH）、促黄体生成素（LH）、胰岛素和促肾上腺皮质激素（ACTH）显示出可忽略不计的交叉反应性。对置换曲线的Scatchard分析表明，125I-OPRL与其受体具有高亲和力，颗粒细胞受体的解离常数（Kd）为7.4 - 7.7×10（-10）M，且随着卵泡增大无变化。相比之下，催乳素的特异性结合随着卵泡成熟而显著降低，结合位点/细胞从小卵泡中的555个明显减少到大（排卵前）卵泡中的300个。所显示的Kd值在体内容易达到的催乳素浓度范围内，并且与我们实验室及其他地方从乳腺和其他组织获得的催乳素受体值高度一致。因此，这些研究可能为更好地理解催乳素在卵巢功能中的作用提供基础。
