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类激素受体的调控机制。所得结果如下。（1）分析了促性腺激素释放激素（GnRH）cDNA的全碱基序列。发现垂体中GnRH受体的mRNA表达仅限于LH和FSH细胞。GnRH在成熟卵泡和闭锁卵泡中的表达提示GnRH在卵泡成熟和闭锁中的作用。（2）对不同动物的促性腺激素受体cDNA进行分析。在鹌鹑中完成了细胞外结构域的测序，这是在鸟类中的首次发现。本研究完成了部分胞外区抗体表位的测定，人工调控光周期对野生鸟类受体数量的调控也得到了预期的结果。（3）放射受体分析显示，子宫内存在催乳素受体，且催乳素受体优先分布于子宫肌层细胞。子宫的催乳素结合能力因催乳素而升高，并有因雌激素而增加的趋势。（4）免疫组织化学研究显示，部分GnRH神经元呈Isotocin免疫反应阳性，表明GnRH与Isotocin在功能上存在相关性。

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.