Funakoshi Kengo, Nakano Masato, Atobe Yoshitoshi, Goris Richad C, Kadota Tetsuo, Yazama Futoshi
Department of Neuroanatomy, Yokohama City University School of Medicine, 3-9 Fukuura, Yokohama, 236-0004, Japan.
Cell Tissue Res. 2006 Jan;323(1):27-41. doi: 10.1007/s00441-005-0013-3. Epub 2005 Sep 2.
In mouse ontogeny, neurons immunoreactive for transient receptor potential vanilloid receptor 1 (TRPV1) were observed primarily in the dorsal root ganglia (DRG) at embryonic day 13 (E13). In the embryonic period, the number of TRPV1(+) neurons decreased, but then gradually increased postnatally. Some of TRPV1(+) neurons were also immunoreactive for calcitonin gene-related peptide (CGRP). At postnatal day 7 (P7), 66% of CGRP(+) neurons were TRPV1(+), and 55% of TRPV1(+) neurons were also CGRP(+) in the L4 DRG. In the peripheral organs, TRPV1-immunorective nerve fibers were transiently observed in the skin at E14. They were also observed in the urinary tract at E14, and in the rectum at E15. Many TRPV1(+) nerve fibers in these organs were also CGRP(+). At P1, TRPV1(+) nerve fibers were observed in the respiratory organs, and to a lesser extent in the stomach, colon, skin, and skeletal muscles. The number of TRPV1(+) nerve fibers on each organ gradually increased postnatally. At P7, TRPV1(+) nerve fibers were also observed in the small intestine and kidneys. The percentage of total TRPV1(+) nerve fibers that co-localized with CGRP was greater in most organs at P7 than at P1. The present results indicate that TRPV1 expression on peripheral processes differs among organs. The differential time course of TRPV1 expression in the cell bodies might be related to the organs to which they project. Co-localization of TRPV1 with CGRP on nerve fibers also varies among organs. This suggests that the TRPV1-mediated neuropeptide release that occurs in certain pathophysiologic conditions also varies among organs.
在小鼠个体发育过程中，胚胎第13天（E13）时，主要在背根神经节（DRG）中观察到对瞬时受体电位香草酸受体1（TRPV1）免疫反应阳性的神经元。在胚胎期，TRPV1（+）神经元数量减少，但出生后逐渐增加。一些TRPV1（+）神经元对降钙素基因相关肽（CGRP）也呈免疫反应阳性。在出生后第7天（P7），L4背根神经节中66%的CGRP（+）神经元是TRPV1（+），55%的TRPV1（+）神经元也是CGRP（+）。在周围器官中，E14时在皮肤中短暂观察到TRPV1免疫反应性神经纤维。E14时在泌尿道中也观察到它们，E15时在直肠中观察到。这些器官中许多TRPV1（+）神经纤维也是CGRP（+）。在P1时，在呼吸器官中观察到TRPV1（+）神经纤维，在胃、结肠、皮肤和骨骼肌中观察到的程度较小。每个器官上TRPV1（+）神经纤维的数量出生后逐渐增加。在P7时，在小肠和肾脏中也观察到TRPV1（+）神经纤维。在大多数器官中，P7时与CGRP共定位的TRPV1（+）神经纤维总数的百分比高于P1时。目前的结果表明，TRPV1在外周神经纤维上的表达在不同器官之间存在差异。TRPV1在细胞体中的表达的不同时间进程可能与其投射的器官有关。TRPV1与CGRP在神经纤维上的共定位在不同器官之间也有所不同。这表明在某些病理生理条件下发生的TRPV1介导的神经肽释放也因器官而异。
