Upregulated expression of neuropeptide Y in hypothalamic-pituitary system of rats by chronic dexamethasone administration
Upregulated expression of neuropeptide Y in hypothalamic-pituitary system of rats by chronic dexamethasone administration
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DOI：
10.1016/j.neures.2007.11.005
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发表时间：
2008-03-01
影响因子：
2.9
通讯作者：
Hisano, Setsuji
中科院分区：
文献类型：
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作者：
Konno, Jinko;Yoshida, Sachine;Hisano, Setsuji
为研究肾上腺皮质激素对下丘脑-垂体系统神经肽Y（neuropeptide Y，NPY）合成的影响，采用原位杂交和免疫组织化学方法检测了地塞米松（一种人工合成的糖皮质激素）处理的大鼠下丘脑-垂体系统NPY的表达。每天给大鼠注射地塞米松（0.2 mg/100 g/天，持续10天，sc）或芝麻油（溶剂对照），或不注射（完整对照）。促肾上腺皮质激素释放激素或神经垂体后叶素II（一种加压素载体蛋白）的相对染色面积在溶媒对照组正中隆起的外部区域增加，但与地塞米松注射组的完整对照相当。注射地塞米松组的外侧区神经肽Y染色纤维静脉曲张的密度显著增加，而内侧区没有，这与弓状核神经肽Y杂交信号水平的增加相一致。双标记实验表明，没有共定位的神经肽与垂体或其他肽检查在单一纤维的正中隆起。在地塞米松注射组中，在少数垂体细胞中可检测到NPY mRNA和肽的表达，其中一些是促皮质激素细胞。这些结果表明，NPY在下丘脑-垂体-肾上腺轴中起激素作用。(C)2007 Elsevier爱尔兰有限公司和日本神经科学学会。All rights reserved.
To study the effect of adrenal steroids on neuropeptide Y (NPY) synthesis in the hypothalamic-pituitary system, we examined NPY expression in rats treated with dexamethasone (a synthetic glucocorticoid) by in situ hybridization and immunohistochemistry. Rats were injected daily with dexamethasone (0.2 mg/100 g/day for 10 days, sc) or sesame oil (vehicle control), or non-injected (intact control). Relative staining area for corticotropin-releasing hormone or neurophysin II, a vasopressin carrier protein, was increased in the external zone of the median eminence in vehicle control, but was equivalent to that of intact control in the dexamethasone-injected group. Density of NPY-stained fiber varicosities was drastically increased in the external, but not the internal, zone of dexamethasone-injected group, coinciding with the increased NPY hybridization signal level in the arcuate nucleus. Dual-labeling experiments revealed no colocalization of NPY with hypophysiotropic or other peptides examined in single fibers of the median eminence. In the dexamethasone-injected group, expressions of NPY mRNA and peptide were detectable in a few pituitary cells, with some being corticotropes. These results suggest that NPY plays hormonal roles in the hypothalamic-pituitary-adrenal axis. (C) 2007 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.