Comparative endocrinological study on hormone receptors related to reproductive function

本项目旨在阐明与生殖功能相关的肽激素受体的调控机制。所得结果如下：(1)分析了编码促性腺激素释放激素（GnRH）的cDNA全碱基序列。垂体中GnRH受体mRNA的表达仅限于LH和FSH细胞。此外，在成熟和闭锁的卵巢卵泡中的表达表明GnRH在卵泡成熟和闭锁中的作用。(2)分析了不同动物的促性腺激素受体cdna。在鹌鹑中完成了细胞外结构域的测序，这是在鸟类中首次发现。部分完成了细胞外结构域抗体抗原表位的测定。人工调节光周期对野生鸟类受体数量的调节结果与预期一致。(3)放射受体测定显示子宫中有特异性催乳素受体优先存在于子宫肌层细胞中。子宫泌乳素结合能力在泌乳素作用下升高，在雌激素作用下有升高的趋势。(4)侏儒gourami的免疫组化研究显示部分GnRH神经元表现出异催产素免疫反应性，提示GnRH与异催产素功能相关。

This project aims to clarify the regulatory mechanism of peptide hormone receptors relating reproductive function. The results obtained are as follows.(1)The whole base sequence of cDNA encoding gonadotropin-releasing hormone (GnRH) was analyzed. The expression of mRNA for GnRH receptors in the pituitary is found to be limited to LH and FSH cells. Furthermore, the expression in the ovarian follicles both maturing and atreticindicates the role of GnRH in follicular maturation and atresia.(2)Gonadotropin receptor cDNAs were analyzed in various animal species. Sequencing of extracellular domain was completed in the quail, first discovery in avian species. The determination of epitopes of raised antibody for the extracellular domain was partly completed.Regulation of receptor number by artificial manipulation of photoperiod in wild birds showed the results as expected.(3)Radioreceptor assay revealed that the uterus contains specific prolactin receptors preferentially in the myometrial cells. The prolactin binding capacity of the uterus was elevated by prolactin and tended to increase by estrogen.(4)Immunohistochemical study in dwarf gourami revealed that some GnRH neurons showed isotocin immunoreactivity, indicating functional correlation between GnRH and isotocin.