An important piece of evidence has shown that molecules acting on cannabinoid receptors influence gastrointestinal motility and induce beneficial effects on gastrointestinal inflammation and visceral pain. The aim of this investigation was to immunohistochemically localize the distribution of canonical cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) and the cannabinoid-related receptors transient potential vanilloid receptor 1 (TRPV1), transient potential ankyrin receptor 1 (TRPA1), and serotonin receptor 5-HT1a (5-HT1aR) in the myenteric plexus (MP) of pig ileum. CB1R, TRPV1, TRPA1, and 5-HT1aR were expressed, with different intensities in the cytoplasm of MP neurons. For each receptor, the proportions of the immunoreactive neurons were evaluated using the anti-HuC/HuD antibody. These receptors were also localized on nerve fibers (CB1R, TRPA1), smooth muscle cells of tunica muscularis (CB1R, 5-HT1aR), and endothelial cells of blood vessels (TRPV1, TRPA1, 5-HT1aR). The nerve varicosities were also found to be immunoreactive for both TRPV1 and 5-HT1aR. No immunoreactivity was documented for CB2R. Cannabinoid and cannabinoid-related receptors herein investigated showed a wide distribution in the enteric neurons and nerve fibers of the pig MP. These results could provide an anatomical basis for additional research, supporting the therapeutic use of cannabinoid receptor agonists in relieving motility disorders in porcine enteropathies.

中文翻译：

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猪回肠肌间丛中的大麻素和大麻素相关受体

一项重要的证据表明，作用于大麻素受体的分子会影响胃肠道运动，并对胃肠道炎症和内脏疼痛产生有益的影响。本研究的目的是通过免疫组织化学方法定位经典大麻素受体 1 型 (CB1R) 和 2 型 (CB2R) 以及大麻素相关受体瞬时电位香草酸受体 1 (TRPV1)、瞬时电位锚蛋白受体 1 (TRPA1)、以及猪回肠肌间丛 (MP) 中的血清素受体 5-HT1a (5-HT1aR)。MP神经元细胞质中表达CB1R、TRPV1、TRPA1和5-HT1aR，但表达强度不同。对于每种受体，使用抗 HuC/HuD 抗体评估免疫反应性神经元的比例。这些受体还定位于神经纤维（CB1R、TRPA1）、肌层平滑肌细胞（ CB1R、5-HT1aR）和血管内皮细胞（TRPV1、TRPA1、5-HT1aR）。还发现神经静脉曲张对 TRPV1 和 5-HT1aR 均具有免疫反应性。没有记录 CB2R 的免疫反应性。本文研究的大麻素和大麻素相关受体显示在猪 MP 的肠神经元和神经纤维中广泛分布。这些结果可以为进一步的研究提供解剖学基础，支持大麻素受体激动剂在缓解猪肠病动力障碍方面的治疗用途。