Expression of vesicular glutamate transporter-2 in gonadotropin-releasing hormone neurons of the adult male rat
Expression of vesicular glutamate transporter-2 in gonadotropin-releasing hormone neurons of the adult male rat
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DOI：
10.1210/en.2004-0589
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发表时间：
2004-09-01
期刊：
影响因子：
4.8
通讯作者：
Liposits, Z
中科院分区：
文献类型：
--
作者：
Hrabovszky, E;Turi, GF;Liposits, Z
最近克隆的谷氨酸囊泡转运蛋白（VGLUT1-3）的异构体选择性地将谷氨酸积累到兴奋性轴突末端的突触囊泡中，并被视为谷氨酸能神经元的可靠标记。我们目前的研究提供了双标记原位杂交证据，几乎所有（99.5%）GnRH神经元在成年雄性大鼠视前区表达VGLUT2 mRNA。采用双标记免疫荧光实验检测VGLUT2蛋白在GnRH轴突末端的存在。对GnRH分泌轴突的主要终端区终板血管器官和正中隆起外区进行共聚焦激光显微分析，发现在GnRH轴突终端常发生VGLUT2免疫反应。这些mRNA杂交和免疫细胞化学数据表明，成年雄性大鼠的GnRH神经元具有显著的谷氨酸能特征。内源性谷氨酸在调节促性腺激素分泌中的生理意义有待阐明。
Isoforms of the recently cloned vesicular glutamate transporters (VGLUT1-3) selectively accumulate glutamic acid into synaptic vesicles in excitatory axon terminals and are viewed as reliable markers for glutamatergic neurons. Our present studies provided dual-label in situ hybridization evidence that virtually all (99.5%) GnRH neurons express VGLUT2 mRNA in the preoptic region of the adult male rat. Dual-label immunofluorescent experiments were carried out to examine the presence of VGLUT2 protein in GnRH axon terminals. Confocal laser microscopic analysis of the organum vasculosum of the lamina terminalis and the external zone of the median eminence, the major termination fields for GnRH-secreting axons, demonstrated the frequent occurrence of VGLUT2 immunoreactivity in GnRH axon terminals. Together these mRNA hybridization and immunocytochemical data indicate that GnRH neurons of the adult male rat possess marked glutamatergic characteristics. The physiological significance of endogenous glutamate in the regulation of gonadotropin secretion requires clarification.