Metsikkö M K, Rajaniemi H J
Biochem J. 1984 Dec 1;224(2):467-71. doi: 10.1042/bj2240467.
Specific anti-(lutropin receptor) antibodies were produced by immunizing rabbits with lutropin receptor purified from pseudopregnant rat ovary. The anti-receptor serum at 1:100 dilution together with anti-(rabbit gamma-globulin) serum immunoprecipitated 70% of 3H-labelled, purified lutropin receptor and 42% of 125I-chorio-gonadotropin-receptor complex. The antiserum inhibited hormone binding to rat ovarian particles. Pseudopregnant rat ovarian particles were labelled with periodate/NaB3H4 and solubilized with Triton X-100. The Triton X-100 extract was subjected to immunoprecipitation using the anti-receptor serum. When the immunoprecipitate was dissolved and analysed by polyacrylamide-gel electrophoresis in sodium dodecyl sulphate under reducing conditions followed by fluorography, a receptor polypeptide with an apparent Mr 95000 was detected. A receptor down-regulating dose of choriogonadotropin was injected into pseudopregnant rats and their ovaries were removed and homogenized 4 days later, and analysed for immunoprecipitable receptors as above. No receptor molecules were found. Accordingly, the lutropin receptor molecules actually disappear rather than merely become masked from hormone during homologous down-regulation.
用从假孕大鼠卵巢中纯化的促黄体生成素受体免疫家兔，制备出特异性抗（促黄体生成素受体）抗体。1:100稀释的抗受体血清与抗（兔γ球蛋白）血清一起免疫沉淀了70%的3H标记的纯化促黄体生成素受体和42%的125I-绒毛膜促性腺激素-受体复合物。该抗血清抑制激素与大鼠卵巢颗粒的结合。用高碘酸盐/NaB3H4标记假孕大鼠卵巢颗粒，并用 Triton X-100使其溶解。用抗受体血清对Triton X-100提取物进行免疫沉淀。当免疫沉淀物溶解后，在还原条件下于十二烷基硫酸钠中进行聚丙烯酰胺凝胶电泳，随后进行荧光显影分析，检测到一条表观分子量为95000的受体多肽。给假孕大鼠注射下调受体剂量的绒毛膜促性腺激素，4天后取出其卵巢并匀浆，按上述方法分析可免疫沉淀的受体。未发现受体分子。因此，在同源下调过程中，促黄体生成素受体分子实际上消失了，而不仅仅是对激素隐匿起来。
