Domoto T, Zhang W B, Tsumori T, Oki M
Department of Anatomy, Shimane Medical University, Izumo, Japan.
J Auton Nerv Syst. 1994 Oct;49(2):135-46. doi: 10.1016/0165-1838(94)90133-3.
The distribution of nerve fibers containing enkephalin (ENK)-like immunoreactivity was examined in the rectum of aganglionosis rats (AGRs) which completely lack the intramural ganglion cells in the large intestine, and was compared with that of their normal littermates. Furthermore, Met5-enkephalin-Arg6-Gly7-Leu8 (MEAGL)-like immunoreactive neurons projecting to the rectum were examined using retrograde tracing combined with immunohistochemistry in the major pelvic ganglion of normal male rats. In the intermuscular space of the aganglionic rectum of AGRs, unlike the pattern of the normal intermuscular plexus, moderate numbers of ENK-like-immunoreactive fibers were arranged in an irregular, coarse network; greatly diminished numbers of immunoreactive fibers were found in the submucosa. No ENK-like-immunoreactive fibers were seen in the circular muscle layer and mucosa. In the normal rat rectum, ENK-like-immunoreactive fibers were seen throughout all layers, and immunoreactive nerve cells were found predominantly in the myenteric plexus of colchicine-treated animals. Fluoro-Gold injected into the upper rectum labelled numerous principal ganglion neurons in the major pelvic and inferior mesenteric ganglia. Less than 10% of tracer-labelled neurons were positive for fluorescein immunolabelling of MEAGL in the major pelvic ganglion; no immunoreactive neurons were found in the inferior mesenteric ganglion. In the major pelvic ganglion of the colchicine-treated normal rats, about 5% of principal ganglion neurons were immunoreactive for MEAGL. Comparison of serial paraffin sections of the major pelvic ganglion stained for tyrosine hydroxylase (TH), MEAGL and vasoactive intestinal polypeptide (VIP), respectively, revealed that more than half of MEAGL-like immunoreactive neurons were also positive for TH; there was no case showing co-existence of MEAGL with VIP in the principal neurons. These results indicate that a small number of enkephalin-containing neurons in the major pelvic ganglion project to the rectum, and that more than half of these neurons are postganglionic sympathetic. They may terminate mainly in the myenteric ganglia in the rectum.
在完全缺乏大肠壁内神经节细胞的无神经节大鼠（AGR）的直肠中，检查了含有脑啡肽（ENK）样免疫反应性的神经纤维分布，并与它们的正常同窝仔鼠进行了比较。此外，在正常雄性大鼠的主要盆腔神经节中，使用逆行追踪结合免疫组织化学技术，检查了投射到直肠的Met5-脑啡肽-Arg6-Gly7-Leu8（MEAGL）样免疫反应性神经元。在AGR无神经节直肠的肌间间隙中，与正常肌间神经丛的模式不同，中等数量的ENK样免疫反应性纤维以不规则的粗网络形式排列；在黏膜下层发现免疫反应性纤维数量大大减少。在环肌层和黏膜中未见ENK样免疫反应性纤维。在正常大鼠直肠中，ENK样免疫反应性纤维见于所有层，免疫反应性神经细胞主要见于秋水仙碱处理动物的肌间神经丛。将荧光金注入直肠上段，标记了主要盆腔神经节和肠系膜下神经节中的许多主要神经节神经元。在主要盆腔神经节中，不到10%的示踪剂标记神经元对MEAGL的荧光免疫标记呈阳性；在肠系膜下神经节中未发现免疫反应性神经元。在秋水仙碱处理的正常大鼠的主要盆腔神经节中，约5%的主要神经节神经元对MEAGL呈免疫反应性。分别对主要盆腔神经节的连续石蜡切片进行酪氨酸羟化酶（TH）、MEAGL和血管活性肠肽（VIP）染色的比较显示，超过一半的MEAGL样免疫反应性神经元对TH也呈阳性；在主要神经元中没有显示MEAGL与VIP共存的情况。这些结果表明，主要盆腔神经节中少数含脑啡肽的神经元投射到直肠，并且这些神经元中超过一半是节后交感神经元。它们可能主要终止于直肠的肌间神经节。
