Dudás Bertalan, Merchenthaler István
Department of Pharmacology and Experimental Therapeutics, Loyola University Chicago, Strich School of Medicine, Maywood, Illinois 60153, USA.
J Clin Endocrinol Metab. 2003 Apr;88(4):1842-8. doi: 10.1210/jc.2002-021416.
Although several studies indicated that leu-enkephalin controls gonadal function, the morphological substrate of this modulation is unknown. To reveal potential interaction sites between leu-enkephalin and LH-releasing hormone (LHRH) in the hypothalamus, the distribution and connections of leu-enkephalin-immunoreactive (IR) and LHRH-IR systems were examined in the human diencephalon using double-label immunohistochemistry. First the leu-enkephalin-IR and LHRH-IR neural elements were mapped, then the maps of the two different neurotransmitter systems were superimposed unveiling the overlapping areas. The putative juxtapositions between leu-enkephalin-IR and LHRH-IR structures were revealed with double label immunocytochemistry. Close contacts were detected in the medial preoptic area and in the infundibulum/median eminence. In these areas, diaminobenzidine-silver-intensified, black leu-enkephalin-IR fibers abutted fusiform, brown, diaminobenzidine-labeled LHRH neurons often forming multiple contacts. Examination of semithin sections of these close associations with the aid of oil immersion revealed no cleft between the contacting LHRH-IR and leu-enkephalin-IR elements. Our findings indicate that the juxtapositions between LHRH-IR and leu enkephalin-IR neurons may be functional synapses forming the morphological substrate of the leu-enkephalin-modulated LHRH secretion in the human diencephalon. Moreover, the wide distribution of leu-enkephalin-IR elements suggests leu-enkephalin control of other diencephalic functions as well.
尽管多项研究表明亮氨酸脑啡肽可控制性腺功能，但这种调节作用的形态学基础尚不清楚。为了揭示下丘脑内亮氨酸脑啡肽与促黄体激素释放激素（LHRH）之间潜在的相互作用位点，利用双标记免疫组织化学技术，对人类间脑内亮氨酸脑啡肽免疫反应性（IR）和LHRH-IR系统的分布及连接进行了研究。首先绘制亮氨酸脑啡肽-IR和LHRH-IR神经元的分布图，然后将这两种不同神经递质系统的图谱叠加，以揭示重叠区域。通过双标记免疫细胞化学技术揭示亮氨酸脑啡肽-IR与LHRH-IR结构之间的假定并列关系。在内侧视前区和漏斗/正中隆起处检测到紧密接触。在这些区域，经二氨基联苯胺银强化的黑色亮氨酸脑啡肽-IR纤维紧邻梭形、棕色、经二氨基联苯胺标记的LHRH神经元，常形成多个接触点。借助油浸对这些紧密关联区域的半薄切片进行检查发现，相互接触的LHRH-IR和亮氨酸脑啡肽-IR成分之间没有间隙。我们的研究结果表明，LHRH-IR与亮氨酸脑啡肽-IR神经元之间的并列关系可能是功能性突触，构成了人类间脑内亮氨酸脑啡肽调节LHRH分泌的形态学基础。此外，亮氨酸脑啡肽-IR成分的广泛分布表明亮氨酸脑啡肽也控制着间脑的其他功能。
