猪食管神经支配的神经化学研究——一氧化氮类及肽类成分在平滑肌中的分布(英文)

采用免疫荧光组织化学技术及迷走神经切断术,探讨猪食管一氧化氮类及肽类神经支配的神经化学特性。在光学显微镜下可观察到肌间神经丛及粘膜下神经丛中有部分神经元呈nNOS、VIP、GAL、NPY、PACAP、L-ENK、SP、5-HT及CB免疫阳性,但未见CGRP及SOM阳性神经元。nNOS及CB免疫阳性产物主要分布于不同的神经元胞体内。将PGP9.5作为神经元胞体的标记物,并采用免疫荧光免疫组织化学双重染色方法,分别观察了PGP9.5与nNOS、VIP、SP的双标情况。结果如下:(1)nNOS免疫阳性神经元约占PGP9.5标记神经元总数的63%,而VIP免疫阳性神经元约占36%,SP免疫阳性神经元约占28%;(2)神经节内神经元的平均数量呈现吻尾方向的递增趋势,且食管腹段神经丛内神经节数量明显高于食管其他部位;(3)食管肌层内VIP/GAL/NPY免疫阳性纤维分布最广,其中部分阳性纤维同时呈nNOS或PACAP免疫阳性;SP和/或L-ENK免疫阳性纤维在粘膜肌层的分布明显多于平滑肌层。CGRP阳性纤维非常少见,这一点不同于对其他动物的观察结果;(4)经一侧迷走神经切断后,肌间神经丛内PACAP及5-HT免疫阳性纤维明显减少,提示这些纤维可能来源于迷走神经;而平滑肌中VIP/GAL/NPY和/或nNOS免疫阳性纤维数量未发现明显变化,可能为内源性来源。

NEUROCHEMICAL MAPPING OF THE PORCINE ESOPHAGEAL INNERVATION--DISTRIBUTION OF THE NITRERGIC AND PEPTIDERGIC COMPONENTS IN THE MUSCULATURE

The neurochemical features of the nitrergic and peptidergic innervation of the porcine esophagus were investigated by means of immunohistochemical methods combined with vagotomy. Neuronal cell bodies in both the submucosal and the myenteric plexus (MP) were detected immunoreactivities for nNOS, VIP, GAL, NPY, PACAP, L-ENK, SP, 5-HT and CB, while CGRP- and SOM-immunoreactive (ir) somata were not encountered. In addition, nNOS- and CB-ir myenteric neurons constituted the separate enteric subpopulations. Double immunostainings with a general neuronal marker (PGP_ 9.5 ) and the specific markers, such as nNOS, VIP and SP revealed (1) nNOS-ir myenteric neurons in the porcine esophagus accounted for a higher percentage (63%) of all esophageal intrinsic PGP_ 9.5 -ir neurons in comparison of VIP-ir (36%) and SP-ir populations (28%); (2) An increasing rostrocaudal gradient in the number of myenteric neurons per ganglion as well as a significantly higher number of enteric ganglia within both plexuses in the abdominal segment;(3)The densest nerve fibers within the esophageal musculature were VIP-/GAL-/NPY-ir, some of which also co-expressed nNOS and/or PACAP immunoreactivity. The number of L-ENK- and/or SP-ir fibers was significantly higher in lamina muscularis mucosae (LMM) than in tunica muscularis externa (TME). In contrast to reports in other species, CGRP-ir fibers within the porcine esophagus constituted a very limited population and were extrinsic;(4)Vagotomy experiments revealed an obvious decrease of PACAP-and 5-HT-ir nerve fibers within the MP, suggesting that these fibers originate from the vagal nerve, while these nNOS- and/or VIP-/GAL-/NPY-ir fibers innervating both the TME and the LMM did not appear to be significantly affected by the vagotomy procedure, possibly being the intrinsic origin.