Ballesta J, Carlei F, Bishop A E, Steel J H, Gibson S J, Fahey M, Hennessey R, Domin J, Bloom S R, Polak J M
Department of Histochemistry, Royal Postgraduate Medical School, Hammersmith Hospital, London, U.K.
Neuroscience. 1988 Jun;25(3):797-816. doi: 10.1016/0306-4522(88)90037-1.
Neuromedin U is a newly described regulatory peptide, found by radioimmunoassay in significant concentrations in both the brain and gut of the rat. The aim of the present study was to localize this peptide immunoreactivity to discrete structures of the gut and brain and to map its distribution using immunocytochemistry. In the gut, neuromedin U was confined to nerve fibres mainly in the myenteric and submucous plexuses and the mucosa of all areas except stomach. Immunoreactive ganglion cells were seen in both ganglionated plexuses and their number did not increase following colchicine administration. This observation and the finding that the population of neuromedin U-immunoreactive nerves in the ileum was not affected by complete extrinsic denervation indicated that the nerves are mostly intrinsic in origin. Colocalization studies revealed neuromedin U and calcitonin gene-related peptide were present in the same myenteric and submucosal ganglion cells. Transection experiments showed that, like calcitonin gene-related peptide-immunoreactive nerves, fibres containing neuromedin U project for very short distances in both an oral and anal direction. At the electron microscopic level, neuromedin U immunoreactivity, demonstrated using the immunogold technique, was localized to large granular vesicles. In the central nervous system, neuromedin U immunoreactivity was localized to fibres which were widespread throughout the brain, except in the cerebellum. The presence of neuromedin U-immunoreactive cell bodies was restricted to the rostrocaudal part of the arcuate nucleus. Colocalization studies showed that a proportion of the neuromedin U-immunoreactive cell bodies in the arcuate nucleus also contained pro-opiomelanocortin. Neuromedin U-immunoreactive fibres were first detected in the rat intestinal mucosa at day 1 after birth. In the brain, the arcuate nucleus showed neuromedin U-immunoreactive neuronal cell bodies at E16 but not at E14. In conclusion, neuromedin U is a new member of the group of molecules known as brain-gut peptides.
神经介素U是一种新发现的调节肽，通过放射免疫分析法在大鼠的脑和肠道中均检测到其高浓度存在。本研究的目的是利用免疫细胞化学技术将该肽的免疫反应性定位到肠道和脑的离散结构上，并绘制其分布图。在肠道中，神经介素U主要局限于肌间神经丛、黏膜下神经丛以及除胃以外所有区域的黏膜中的神经纤维。在有神经节的神经丛中均可见到免疫反应性神经节细胞，给予秋水仙碱后其数量并未增加。这一观察结果以及回肠中神经介素U免疫反应性神经的数量不受完全性外周去神经支配影响这一发现表明，这些神经大多起源于内在神经。共定位研究显示，神经介素U和降钙素基因相关肽存在于同一肌间和黏膜下神经节细胞中。横断实验表明，与降钙素基因相关肽免疫反应性神经一样，含有神经介素U的纤维在口腔和肛门方向的投射距离都非常短。在电子显微镜水平上，利用免疫金技术显示的神经介素U免疫反应性定位于大颗粒囊泡。在中枢神经系统中，神经介素U免疫反应性定位于广泛分布于整个脑（小脑除外）的纤维。神经介素U免疫反应性细胞体仅局限于弓状核的头尾部。共定位研究表明，弓状核中一部分神经介素U免疫反应性细胞体也含有促肾上腺皮质激素原。出生后第1天在大鼠肠黏膜中首次检测到神经介素U免疫反应性纤维。在脑中，弓状核在胚胎第16天显示出神经介素U免疫反应性神经元细胞体，而在胚胎第14天则未显示。总之，神经介素U是脑-肠肽家族的一个新成员。
