Melatonin stimulates thyroid-stimulating hormone accumulation in the thyrotropes of the rat pars tuberalis

被引：0
作者：
Sakamoto S. [1 ]
Nakamura K. [1 ]
Inoue K. [1 ]
Sakai T. [1 ,2 ]
机构：
[1] Department of Regulation Biology, Faculty of Science, Saitama University, Saitama 338-8570, 255 Shimo-ohkubo, Urawa
[2] Laboratory of Cell Biology, Department of Regulation Biology, Saitama University, Saitama 338-8570, 255 Shimo-ohkubo, Urawa
来源：
Histochemistry and Cell Biology | 2000年 / 114卷 / 3期
关键词：
Melatonin; Rat pars tuberalis; Thyroid-stimulating hormone; Thyrotropes;
D O I：
10.1007/s004180000188
中图分类号：
学科分类号：
摘要：
We have reported that the unique thyroid-stimulating hormone-immunoreactive cells (TSH cells) in the intact adult and fetal rat pars tuberalis (PT) show an intense spot-like TSH immunoreaction in the perinuclear region. The present study was designed to investigate the relationship between melatonin and these unique TSH cells. We classified TSH cells in the PT (PT-TSH cells), on the basis of immunoreactivity, into spot-like stained cells (SC) and whole cytoplasm stained cells (WC), and estimated the proportion of each TSH cell type to total cells in the experimental rats by morphometry. Chronic administration of melatonin to control rats leads to an increase of WC in number but a decrease of SC. On the other hand, the intensity of TSH immunore-activity and the number of rat PT-TSH cells significantly decreased after pinealectomy and recovered by melatonin administration. Radioimmunoassay showed that melatonin treatment increased the TSH content in the PT. Moreover, electron microscopy showed that the number of TSH secretory granules in the PT-TSH cells increased in the melatonin-replaced rats. These results demonstrated that melatonin stimulates the accumulation of TSH in the rat PT-TSH cells via secretory granule formation and suggest that melatonin regulates TSH release from PT-TSH cells.
引用
收藏
页码：213 / 218
页数：5
相关论文
共 27 条
  • [1] Badura L.L., Goldman B.D., Anterior pituitary release of prolactin is inhibited by exposure to short photoperiod, J Neuroendocrinol, 9, pp. 341-345, (1997)
  • [2] Baker B.L., Yu Y.Y., Hypophyseal changes induced by thyroid deficiency and thyroxine administration as revealed by immunochemical staining, Endocrinology, 89, pp. 996-1004, (1971)
  • [3] Bergmann M., Wittkowski W., Hoffmann K., Ultrastructural localization of throtropin(TSH)-like immunoreactivity in specific secretory cells of the hypophyseal pars tuberalis in the Djungarian hamster, Phodopus sungorus, Cell Tissue Res, 256, pp. 649-652, (1989)
  • [4] Blithe D., Richards R., Skarulis M., Free alpha molecules from pregnancy stimulate secretion of prolactine from human decidual cells: A novel function for free alpha in pregnancy, Endocrinology, 129, pp. 2257-2259, (1991)
  • [5] Bockers T.M., Bockmann J., Fauteck J.-D., Kreutz M.R., Bock R., Wittkowski W., Pars tuberalis-specific cells in the ovine pituitary do express the common α-chain of glycoprotein hormones: An in situ hybridization and immunocytochemical study, Eur J Endocrinol, 131, pp. 540-546, (1994)
  • [6] Bockers T.M., Niklowitz P., Bockmann J., Fauteck J.D., Wittkowski W., Kreutz M.R., Daily melatonin injections induce cytological changes in pars tuberalis-specific cells similar to short photoperiod, J Neuroendocrinol, 7, pp. 607-613, (1995)
  • [7] Bockers T.M., Bockmann J., Salem A., Niklowitz P., Lerchl A., Huppertz M., Wittkowski W., Kreutz M.R., Initial expression of the common α-chain in hypophyseal pars tuberalis-specific cells in spontaneous recrudescent hamsters, Endocrinology, 138, pp. 4101-4108, (1997)
  • [8] Bockmann J., Bockers T.M., Vennemann B., Niklowitz P., Muller J., Wittkowski W., Sabel B., Kreutz M.R., Short photoperiod-dependent down regulation of thyrotropin-α and -β in hamster pars tuberalis-specific cells is prevented by pinealectomy, Endocrinology, 137, pp. 1804-1813, (1996)
  • [9] Bockmann J., Bockers T.M., Winter C., Wittkowski W., Winterhoff H., Deufel T., Kreutz M.R., Thyrotropin expression in hypophyseal pars tuberalis-specific cells is 3,5,3'-triiodothyronine, thyrotropin-releasing hormone, and pit-1 independent, Endocrinology, 138, pp. 1019-1028, (1997)
  • [10] Gross D.S., Hormone production in the hypophyseal pars tuberalis of intact and hypophysectomized rats, Endocrinology, 112, pp. 733-744, (1983)
123