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The identification of a hoemone secreted by the pars tuberalis cells

结节部细胞分泌的激素的鉴定

基本信息

批准号：
09670027
负责人：
KAMEDA Yoko
金额：
$ 1.47万
依托单位：
Kitasato University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670027/
关键词：
Hypophyseal pars tuberalis Chicken Common alpha-subunit mRNA Luteinizing hormone Chromogranin A Circadian rhythm In situ hybridization Immunoelectron microscopy in situ ハイブリダイゼーション隆起部細胞松果体

项目摘要

The hypophyseal parts tuberalis covers both the infundibular stalk and median eminence as thin cell layers. Despite of its occurrence in large numbers of animal species, the functional significance of the pars tuberalis remains obscure. A majority of the pars tuberalis consist of secretory cells specific to this portion of the pituitary. In contrast to the cells of mammalian species that contain only a few small secretory granules, the specific cells of the chicken pars tuberalis are characterized by the presence of many secretory granules ranging from 90 to 4O0nm in diameter. Almost all cells throughout the pars tuberalis of chickens were immunoreactive for luteinizing hormone (LH) and chromogranin A.Furthermore, immunoelectron microscopy using post-embedding immunogold labeling showed that gold particles representing immunoreactivily for LH were located in all secretory granules of the pars tuberalis cells. Double immunogold labeling confirmed that LH and chromogranin A were colocali … More zed on the same secretory granules. Concerning the ontogeny of the chicken pars tuberalis, the primordium of the pars tuberalis located close to the median eminence was first formed at the lateral-apical end of the pars distalis at 8 days of incubation. The primordium expressed intense signal for common a-subunit mRNA of glycoprotein hormones. In addition, it was immunoreactive for LH and chromogranin A.The pars tuberalis primordium progressively extended along the median eminence with age and reached to the rostoral end at 14 days of incubation. It was confirmed by in situ hybridization that the pars tuberalis cells expressed intense signal for a-subunit mRNA for life. High concentrations of melatonin-binding sites have been observed in the pars tuberalis of various animal species. Under long photo periods (24 his light) for I month, the specific cells of the chicken pars tuberalis were filled with enlarged secretory granules. On the other hand, under short photo periods (22 his dark) for I months, the cytoplasm of the pars tuberalis-specific cells were enlarged in size and revealed only a few small secretory granules. Furthermore, the cells contained numerous niitochondria, increased rough endoplasmic reticulum and Golgi complexes, showing increased cell activity. Northern blot analysis with 32P-labeled a-subunit cDNA exhibited that the amounts of a-subunit mRNA in the chicken pars tuberalis were conspicuously affected by the alterations of circadian rhythms. Less

垂体部结节覆盖漏斗柄和正中隆起为薄层细胞层。尽管它出现在大量的动物物种中，但结节的功能意义仍然不清楚。大部分结节由这部分脑下垂体特有的分泌细胞组成。与哺乳动物细胞只含有少量小的分泌颗粒不同，鸡结节的特殊细胞具有许多直径在90-400 nm之间的分泌颗粒。鸡结节细胞几乎全部为黄体生成素和嗜铬粒素A免疫阳性。此外，用包埋后免疫金标记法的免疫电子显微镜观察表明，黄体生成素免疫活性的金颗粒分布于结节细胞的所有分泌颗粒中。免疫胶体金双标记证实黄体生成素和嗜铬粒蛋白A为同源…在相同的分泌颗粒上做得更多。关于鸡结节的个体发育，位于正中隆起附近的结节原基在孵化8d时首先在远端的外侧顶端形成。原基表达糖蛋白激素共同α-亚单位mRNA的强信号。此外，黄体生成素和嗜铬粒蛋白A免疫反应阳性。结节原始部随着年龄的增长逐渐沿着正中隆起延伸，在孵化14d时达到吻端。原位杂交证实，结节细胞终生表达α-亚单位的强信号。在各种动物的结节部位都观察到了高浓度的褪黑素结合部位。在长时间照相(24His光照)1个月时，鸡结节特定细胞内充满了增大的分泌颗粒。另一方面，在短时照相(22 His暗)下1个月，结节部分特异细胞的细胞质变大，只显示少量的分泌颗粒。此外，细胞内含有大量线粒体，粗面内质网增多，高尔基复合体增多，细胞活性增强。~(32)P标记的α-亚基基因的Northern印迹分析表明，鸡结节α-亚基mRNA的含量明显受昼夜节律变化的影响。较少