Stepien A, Derecka K, Gawronska B, Bodek G, Zwierzchowski L, Shemesh M, Ziecik A J
Institute of Genetics and Animal Breeding of Polish Academy of Sciences, Jastrz biec.
J Physiol Pharmacol. 2000 Dec;51(4 Pt 2):917-31.
High-affinity LH/hCG binding sites have been characterized in bovine, lepine, murine, human uteri and porcine myometrium and endometrium. In the present studies we analyzed these receptors in the porcine cervix. Radioreceptor ligand assays were performed with cell membrane preparations of the cervix which were analyzed for binding sites specificity, capacity and affinity. Corpus luteum and myometrium were used as positive control tissues. In the cervix there was little competition for receptor occupancy between hCG and porcine FSH (1.2%) or bovineTSH, porcine GH and porcine PRL (0.1%, 0.1% and < 0.001%; respectively) but porcine LH could completely inhibit the binding of [125I] hCG. There was not binding for LH/hCG in crude membrane preparations of kidney or skeletal muscle. The concentration (fmol/mg protein) of cervical LH/hCG receptor did not vary significantly during particular phases of the estrous cycle, except the early luteal phase (Days 6-7) when the level of LH receptors was very low (p < 0.05). The affinity of uterine LH/hCG binding sites in the cervix and the myometrium was not different from the affinity of LH/hCG binding sites in luteal cells. The porcine cervix as well as the myometrium contains a 75- and 48-kDa immunoreactive LH/cCG receptor proteins similar to corpus luteum. Southern blot of RT-PCR products performed to enhance the specificity and sensitivity of LH receptor transcripts determination in uterine tissues revealed that expected fragments of 740 and 470 bp were present in myometrium and corpus luteum. The cervix showed only 740 bp fragment. In situ hydridization showed the expression of mRNA for LH receptor in the epithelium of the cervix. Immunoreactive staining for LH/hCG receptors was also observed only in epithelial cells of the cervical tissue. Our studies are probably the first evidence demonstrating the specific LH/hCG binding sites in female cervix.
在牛、兔、鼠、人的子宫以及猪的子宫肌层和子宫内膜中已鉴定出高亲和力的促黄体生成素/人绒毛膜促性腺激素（LH/hCG）结合位点。在本研究中，我们分析了猪子宫颈中的这些受体。用子宫颈的细胞膜制剂进行放射受体配体测定，并分析其结合位点的特异性、容量和亲和力。黄体和子宫肌层用作阳性对照组织。在子宫颈中，hCG与猪促卵泡素（FSH）（1.2%）、牛促甲状腺激素（TSH）、猪生长激素（GH）和猪催乳素（PRL）（分别为0.1%、0.1%和<0.001%）之间对受体占据的竞争很小，但猪LH能完全抑制[125I]hCG的结合。在肾脏或骨骼肌的粗制膜制剂中未检测到LH/hCG结合。除了黄体早期（第6 - 7天）LH受体水平非常低（p < 0.05）外，子宫颈LH/hCG受体的浓度（fmol/mg蛋白质）在发情周期的特定阶段没有显著变化。子宫颈和子宫肌层中子宫LH/hCG结合位点的亲和力与黄体细胞中LH/hCG结合位点的亲和力没有差异。猪子宫颈以及子宫肌层含有与黄体相似的75 kDa和48 kDa免疫反应性LH/hCG受体蛋白。为提高子宫组织中LH受体转录本测定的特异性和敏感性而进行的RT-PCR产物的Southern印迹显示，子宫肌层和黄体中存在预期的740 bp和470 bp片段。子宫颈仅显示740 bp片段。原位杂交显示子宫颈上皮中存在LH受体的mRNA表达。在子宫颈组织的上皮细胞中也仅观察到LH/hCG受体的免疫反应性染色。我们的研究可能是首个证明雌性子宫颈中存在特异性LH/hCG结合位点的证据。
