Progesterone-receptive dopaminergic and neuropeptide Y neurons project from the arcuate nucleus to gonadotropin-releasing hormone-rich regions of the ovine preoptic area
Progesterone-receptive dopaminergic and neuropeptide Y neurons project from the arcuate nucleus to gonadotropin-releasing hormone-rich regions of the ovine preoptic area
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DOI：
10.1159/000090122
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发表时间：
2005-01-01
影响因子：
4.1
通讯作者：
Skinner, DC
中科院分区：
文献类型：
--
作者：
Dufourny, L;Caraty, A;Skinner, DC
孕酮抑制促性腺激素释放激素（GnRH）分泌绵羊通过一个interneuronal系统位于下丘脑内侧基底。这项研究的重点是已知的绵羊GnRH分泌抑制剂，多巴胺和神经肽Y（NPY）。由于酪氨酸羟化酶（TH）和NPY免疫反应神经元的分布与弓状核中的孕酮受体（PR）重叠，我们假设，如果这些神经元至少部分介导孕酮的抑制性反馈信号，那么它们应该共同表达PR。将荧光金（FG）逆行示踪剂注入经雌、孕激素预处理的去卵巢母羊视前区。当FG注射部位包含至少80个GnRH神经元时，使用PR和TH或NPY的双重免疫细胞化学处理来自弓状核的切片。我们发现，30%的PR-免疫反应，12%的TH-含有和21%的NPY-合成神经元项目向这个GnRH丰富的区域。在PR/TH双标记细胞中，分别占PR细胞的21%和TH细胞的31%，22%显示FG标记。在PR/NPY神经元中，分别占PR神经元的19%和NPY神经元的67%，其中26%为FG荧光。这项研究表明，弓状核多巴胺能神经元和NPY神经元的亚群可能会抵消，至少部分，胆甾酮介导的GnRH分泌抑制。版权所有（C）2005 S. Karger AG，巴塞尔。
Progesterone inhibits gonadotropin-releasing hormone ( GnRH) secretion in sheep through an interneuronal system located in the mediobasal hypothalamus. This study focused on known inhibitors of GnRH secretion in sheep, dopamine and neuropeptide Y (NPY). As the distributions of tyrosine hydroxylase (TH)- and NPY-immunoreactive neurons overlap with progesterone receptors ( PR) in the arcuate nucleus, we hypothesized that, if these neurons mediate, at least partially, the inhibitory feedback signal of progesterone, then they should co-express PRs. Fluorogold (FG), a retrograde tracer, was injected into the preoptic area of ovariectomized ewes pretreated with estrogen and progesterone. When the FG injection site encompassed at least 80 GnRH neurons, sections from the arcuate nucleus were processed using dual immunocytochemistry for PR and either TH or NPY. We found that 30% of PR-immunoreactive, 12% of TH-containing and 21% of NPY-synthesizing neurons project toward this GnRH-rich region. Of the PR/TH dual-labeled cells, which represent 21% of PR and 31% of TH cells, respectively, 22% displayed FG labeling. Of the PR/NPY neurons, which account for 19% of PR and 67% of NPY neurons, respectively, 26% were FG fluorescent. This study suggests that subsets of arcuate nucleus dopaminergic and NPY neurons may transduce, at least in part, the progesterone-mediated inhibition of GnRH secretion. Copyright (C) 2005 S. Karger AG, Basel.