Bradbury E J, Burnstock G, McMahon S B
Guy's, King's and St. Thomas' School of Biomedical Sciences, King's College, London, SE1 7EH, United Kingdom.
Mol Cell Neurosci. 1998 Nov;12(4-5):256-68. doi: 10.1006/mcne.1998.0719.
We have studied the distribution and regulation of the P2X3 receptor (a ligand-gated ion channel activated by ATP) in adult dorsal root ganglion (DRG) neurons using a polyclonal antibody. P2X3 receptor immunoreactivity was normally present in about 35% of L4/5 DRG neurons, virtually all small in diameter. In the dorsal horn, P2X3 receptor expression was restricted to the terminals of sensory neurons terminating in lamina IIinner. P2X3 receptors were expressed in approximately equal numbers of sensory neurons projecting to skin and viscera but in very few of those innervating skeletal muscle. P2X3 receptors were found mostly in sensory neurons that bind the lectin IB4. After sciatic nerve axotomy, P2X3 receptor expression dropped by more than 50% in L4/5 DRG. Glial cell line-derived neurotrophic factor (GDNF), delivered intrathecally, completely reversed axotomy-induced down-regulation of the P2X3 receptor. We conclude that P2X3 receptors are normally expressed in nociceptive primary sensory neurons, predominantly the nonpeptidergic nociceptors. P2X3 receptors are down-regulated following peripheral nerve injury and their expression can be regulated by GDNF.
我们使用多克隆抗体研究了P2X3受体（一种由三磷酸腺苷激活的配体门控离子通道）在成年背根神经节（DRG）神经元中的分布和调节。P2X3受体免疫反应性通常存在于约35%的L4/5 DRG神经元中，几乎所有这些神经元直径都很小。在背角，P2X3受体表达仅限于终止于板层II内的感觉神经元的终末。投射到皮肤和内脏的感觉神经元中表达P2X3受体的数量大致相等，但支配骨骼肌的感觉神经元中表达P2X3受体的非常少。P2X3受体主要存在于结合凝集素IB4的感觉神经元中。坐骨神经切断术后，L4/5 DRG中P2X3受体表达下降超过50%。鞘内注射胶质细胞系源性神经营养因子（GDNF）可完全逆转切断轴突诱导的P2X3受体下调。我们得出结论，P2X3受体通常在伤害性初级感觉神经元中表达，主要是无肽伤害感受器。外周神经损伤后P2X3受体下调，其表达可由GDNF调节。
