Ichikawa Hiroyuki, Sugimoto Tomosada
Department of Oral Function and Anatomy, and Biodental Research Center, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
Brain Res. 2004 Feb 13;998(1):130-5. doi: 10.1016/j.brainres.2003.11.019.
The co-expression of P2X3 receptor with the vanilloid receptor subtype I (VR1) and vanilloid receptor 1-like receptor (VRL-1) was examined in the rat trigeminal ganglion (TG) by a double immunofluorescence method. P2X3 receptor-immunoreactive (ir) neurons were predominantly small to medium-sized (range=93.8-1844.4 microm(2), mean+/-S.D.=503.8+/-286.5 microm(2)); 35% and 9% of P2X3 receptor-ir TG neurons were immunoreactive for VR1 and VRL-1, respectively. Small and medium-sized P2X3 receptor-ir neurons contained VR1-immunoreactivity (ir), whereas medium-sized and large P2X3 receptor-ir neurons showed VRL-1-ir. The retrograde tracing and immunohistochemical methods revealed that 30% of the TG neurons retrogradely labeled from the facial skin and tooth pulp exhibited P2X3 receptor-ir. The co-expression of P2X3 receptor and VR1 was detected in 16% of cutaneous TG neurons and 6% of tooth pulp neurons. On the other hand, the co-expression of P2X3 receptor and VRL-1 was common in tooth pulp neurons (23%) and rare in cutaneous TG neurons (8%). In the tooth pulp, 95% of P2X3 receptor-ir TG neurons contained VRL-1-ir. The present study indicates that P2X3 receptor-ir TG neurons, which co-express VR-ir, are abundant in the facial skin. The tooth pulp is probably innervated by TG neurons, which contain both P2X3-and VRL-1-ir.
采用双重免疫荧光法检测大鼠三叉神经节（TG）中P2X3受体与香草酸受体亚型I（VR1）和类香草酸受体1样受体（VRL-1）的共表达情况。P2X3受体免疫反应性（ir）神经元主要为中小型（范围=93.8 - 1844.4平方微米，平均±标准差=503.8±286.5平方微米）；分别有35%和9%的P2X3受体ir TG神经元对VR1和VRL-1呈免疫反应性。中小型P2X3受体ir神经元含有VR1免疫反应性（ir），而中大型P2X3受体ir神经元显示VRL-1-ir。逆行追踪和免疫组织化学方法显示，从面部皮肤和牙髓逆行标记的TG神经元中有30%表现出P2X3受体-ir。在16%的皮肤TG神经元和6%的牙髓神经元中检测到P2X3受体与VR1的共表达。另一方面，P2X3受体与VRL-1的共表达在牙髓神经元中很常见（23%），而在皮肤TG神经元中很少见（8%）。在牙髓中，95%的P2X3受体ir TG神经元含有VRL-1-ir。本研究表明，共表达VR-ir的P2X3受体ir TG神经元在面部皮肤中丰富。牙髓可能由同时含有P2X3和VRL-1-ir的TG神经元支配。
