Neuromedin B stimulates the hypothalamic-pituitary-gonadal axis in male rats
Neuromedin B stimulates the hypothalamic-pituitary-gonadal axis in male rats
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DOI：
10.1016/j.regpep.2013.10.002
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发表时间：
2013-11-10
影响因子：
--
通讯作者：
Murphy, K. G.
中科院分区：
文献类型：
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作者：
Boughton, C. K.;Patel, S. A.;Murphy, K. G.
神经介肽B（NMB）是哺乳动物中发现的高度保守的铃蟾肽相关肽。NMB mRNA在中枢神经系统（CNS）中检测到，并且在大鼠下丘脑中高度表达，特别是内侧视前区和弓状核。哺乳动物蛙皮素受体家族由三种密切相关的G蛋白偶联受体Bali BB 2和BB 3组成。BB 1受体亚型对NMB具有最高的亲和力。NMB在大鼠甲状腺轴和应激轴的调节中具有良好的记录作用。然而，很少有关于NMB在调节下丘脑-垂体-性腺（HPG）轴中的作用的可用数据。已知NMB受体在永生化的促性腺激素释放激素（GnRH）释放GT 1 -7细胞和小鼠前脑GnRH神经元中表达，并且垂体前叶NMB免疫反应性因性类固醇环境的变化而改变。脑室内（ICV）给予成年雄性大鼠NMB（10 nmol）在注射后30分钟显著增加血浆促黄体生成激素（LH）水平（血浆LH ng/ml;生理盐水0.69 +/-0.07，10 nmol NMB 133 +/-0.17，P < 0.01）。在体外实验中，NMB刺激雄性大鼠下丘脑外植体和下丘脑GT 1 -7细胞释放GnRH。NMB对雄性大鼠垂体前叶外植体或垂体L β T2细胞体外LH释放无显著影响，这些结果表明NMB通过下丘脑GnRH刺激HPG轴的作用以前未见报道。现在需要进一步的工作，以确定受体介导的NMB对生殖轴的影响和NMB在生殖中的生理作用。(C)2013爱思唯尔有限公司版权所有。
Neuromedin B (NMB) is a highly conserved bombesin-related peptide found in mammals. NMB mRNA is detected in the central nervous system (CNS) and is highly expressed in the rat hypothalamus, in particular the medial preoptic area and the arcuate nucleus. The mammalian bombesin family of receptors consists of three closely related G protein coupled receptors, Bali BB2 and BB3. The BB1 receptor subtype has the highest affinity for NMB. NMB has well documented roles in the regulation of the thyroid axis and the stress axis in rats. However, there is little available data regarding the role of NMB in the regulation of the hypothalamic-pituitary-gonadal (HPG) axis. It is known that the NMB receptor is expressed in immortalised gonadotrophin releasing hormone (GnRH) releasing GT1-7 cells and murine forebrain GnRH neurons, and that anterior pituitary NMB-immunoreactivity is altered by changes in the sex steroid environment. The objective of these studies was thus to further investigate the effects of NMB on the HPG axis.Intracerebroventricular (ICV) administration of NMB (10 nmol) to adult male rats significantly increased plasma luteinising hormone (LH) levels 30 min after injection (plasma LH ng/ml; saline 0.69 +/- 0.07, 10 nmol NMB 133 +/- 0.17, P < 0.01). In vitro, NMB stimulated GnRH release from hypothalamic explants from male rats and from hypothalamic GT1-7 cells. NMB had no significant effect on LH release from anterior pituitary explants from male rats, or from pituitary L beta T2 cells in vitro.These results suggest a previously unreported role for NMB in the stimulation of the HPG axis via hypothalamic GnRH. Further work is now required to determine the receptor mediating the effects of NMB on the reproductive axis and the physiological role of NMB in reproduction. (C) 2013 Elsevier B.V. All rights reserved.