Department of Anatomy, Histology and Embriology, Laboratory for Neurocardiology, University of Split School of Medicine, Šoltanska 2, 21000, Split, Croatia.
Department of Anatomy, Histology and Embriology, Laboratory for Microscopy, University of Split School of Medicine, Šoltanska 2, 21000, Split, Croatia.
Anat Rec (Hoboken). 2019 Sep;302(9):1620-1627. doi: 10.1002/ar.24061. Epub 2019 Jan 20.
Sigma 1 receptor (σ1R) is a non-opioid receptor that modulates pain perception and is strongly expressed in dorsal root ganglion (DRG) neurons. We studied the changes in the expression of σ1R in different sub-populations of DRG neurons during the first 48 hr in a carrageenan-induced inflammation rat model, with σ1R being a possible base for the development of neuropathic pain after inflammation. Twenty Sprague Dawley rats were divided into five groups (N = 4 in each group): the control (C) group was sacrificed immediately; all other animals received an intraplantar injection of 0.1 mL 2% carrageenan and were sacrificed in 6, 12, 24 or 48 hr after the injection and DRGs were collected and processed for immunohistochemistry. σ1R fluorescence intensity decreased slightly but significantly in up to 24 hr post-carrageenan injection in all sub-populations of DRG neurons (ib4+; ib4- medium, ib4- large and ib4- in total; P < 0.05 - P < 0.001), with the exception of the ib4- small neurons (<25 μm; P > 0.05). This decrement was followed by a subsequent increase in σ1R fluorescence intensity 48 hr after the plantar carrageenan injection (P < 0.05 - P < 0.0001). The same trend was also observed in the CGRP+ population of the DRG neurons, in the total population as well as in the CGRP+ small (<25 μm) and larger CGRP (>25 μm) sub-populations (P < 0.05 - P < 0.001). The presented results may contribute to further understanding of role of σ1R in the development of peripheral sensitization during inflammation. They may also be valuable for the therapeutic application of σ1R antagonists, particularly in the adjustment of the antagonist's dosage in a particular time window. Anat Rec, 302:1620-1627, 2019. © 2019 American Association for Anatomy.
Sigma 1 受体（σ1R）是非阿片受体，可调节痛觉，在背根神经节（DRG）神经元中表达强烈。我们研究了在角叉菜胶诱导的炎症大鼠模型中，DRG 神经元不同亚群中 σ1R 表达的变化，σ1R 可能是炎症后神经病理性疼痛发展的基础。20 只 Sprague Dawley 大鼠分为 5 组（每组 4 只）：对照组（C）立即处死；所有其他动物接受足底注射 0.1 mL 2%角叉菜胶，并在注射后 6、12、24 或 48 小时处死，收集和处理 DRG 进行免疫组织化学。在所有 DRG 神经元亚群（ib4+；ib4-中等、ib4-大、ib4-总；P<0.05-P<0.001）中，角叉菜胶注射后 24 小时内 σ1R 荧光强度略有但显著降低，除了 ib4-小神经元（<25 μm；P>0.05）。随后，在足底角叉菜胶注射后 48 小时，σ1R 荧光强度再次增加（P<0.05-P<0.0001）。DRG 神经元中 CGRP+群体、总群体以及 CGRP+小（<25 μm）和较大（>25 μm）亚群中也观察到相同趋势（P<0.05-P<0.001）。这些结果可能有助于进一步了解 σ1R 在炎症期间外周致敏发展中的作用。它们对于 σ1R 拮抗剂的治疗应用也可能具有价值，特别是在特定时间窗调整拮抗剂剂量时。解剖学记录，302：1620-1627，2019。©2019 年美国解剖学会。
