Developmental alteration of hormonal control in exocrine glands

外分泌腺激素控制的发育改变

基本信息

批准号：
08672104
负责人：
HAYASHI Hiroyuki
金额：
$ 0.7万
依托单位：
Kanagawa Dental College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

This study used developmental rat submandibular gland, and studied alteration of hormonal control in exocrine cell.The endoportion of the submandibular gland is called the terminal tubule which is composed of an immature secretory unit. The terminal tubule has three different cells, the acinar cell, the proacinar cell and the terminal tubule cell. The proacinar cell is the precursor of the acinar cell, and all of the proacinar cells differentiate into the acinar cell by the second week after birth. Although the terminal tubule cell is the one which is recognized the most in the submandibular gland of the juvenile period, it does not exist in the adult submandibular gland. The formation of many cytoplasmic vacuoles were first identified in the terminal tubule cells of both sexes at day 18. The marked decrease of secretory granules and the release of vacuoles led to the transformation of the terminal tubules cells into the intercalated duct cells.The TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling) method showed positive reactions in a small number of cells in the terminal tubule cells. The number of positive cells increased until 28 days after birth. Electron microscopy revealed nuclear chromatin aggregation, suggesting apoptosis in terminal tubule cells 21 days or more after birth. These results suggest the close involvement of apoptosis in the regulation of cells constituting the submandibular gland in the postnatal growth of the rat submandibular gland.The immunohistochemical study of estrogen receptor and in situ hybridization study of estrogen receptor mRNA in order to identify the localization of estrogen receptor. In both study, a positive finding was recognized in the terminal tubule cell while no reaction was observed in another cells. The above study results have suggested that the terminal tubule cell is strongly controlled by estrogen.

本研究使用发育中的大鼠颌下腺，研究外分泌细胞激素控制的变化。颌下腺的内部分称为终管，由未成熟的分泌单位组成。终管具有三种不同的细胞：腺泡细胞、腺泡原细胞和终管细胞。腺泡原细胞是腺泡细胞的前身，所有的腺泡原细胞在出生后第二周就分化为腺泡细胞。虽然终管细胞是幼年期颌下腺中最常见的细胞，但在成年颌下腺中并不存在。第18天时，在两性终管细胞中首次发现许多细胞质空泡的形成。分泌颗粒的显着减少和空泡的释放导致终管细胞向闰管细胞转变。末端脱氧核苷酸转移酶介导的dUTP-生物素缺口末端标记)方法显示终末小管细胞中少数细胞出现阳性反应。阳性细胞数量持续增加直至出生后28天。电子显微镜显示核染色质聚集，表明出生后 21 天或更长时间终末小管细胞发生凋亡。这些结果表明细胞凋亡在大鼠颌下腺的出生后生长过程中密切参与构成颌下腺的细胞的调节。通过雌激素受体的免疫组织化学研究和雌激素受体mRNA的原位杂交研究来鉴定雌激素的定位受体。在这两项研究中，在终管细胞中发现了阳性结果，而在其他细胞中没有观察到反应。上述研究结果表明，终末小管细胞受到雌激素的强烈控制。