Guo A, Vulchanova L, Wang J, Li X, Elde R
Department of Cell Biology and Neuroanatomy, University of Minnesota, Minneapolis, MN 55455, USA.
Eur J Neurosci. 1999 Mar;11(3):946-58. doi: 10.1046/j.1460-9568.1999.00503.x.
The vanilloid receptor (VR1) protein functions both as a receptor for capsaicin and a transducer of noxious thermal stimuli. To determine the expression and targetting of this protein, we have generated antisera against both the amino and carboxy termini of VR1. Within the dorsal root and trigeminal ganglia of rats, VR1-immunoreactivity (VR1-ir) was restricted to small and medium sized neurons. VR1-ir was transported into both the central and peripheral processes of these primary afferent neurons, as evidenced by: (i) the presence of VR1-ir in nerve fibres and terminals in lamina I and lamina II of the superficial dorsal horn, and the association of VR1-ir with small diameter nerve fibres in the skin and cornea; (ii) the reduction of VR1-ir in the spinal cord after dorsal rhizotomy; and (iii) the accumulation of VR1-ir proximal to sciatic nerve ligation. At the ultrastructural level, VR1-ir was associated with plasma membranes of neuronal perikarya in dorsal root ganglia and nerve terminals in the dorsal horn. VR1-ir was also seen in nerve fibres and terminals in the spinal trigeminal nucleus and nucleus of the solitary tract. Within a large proportion of dorsal root ganglion neurons and the terminals of their axons, VR1-ir was colocalized with staining for the P2X3 purinoceptor, and with binding sites for the lectin IB4. Surprisingly, VR1-ir did not coexist substantially in nerve fibres and terminals that contain substance P and calcitonin gene-related peptide, suggesting complex mechanisms for the release of these neuropeptides in response to capsaicin application.
香草酸受体（VR1）蛋白既作为辣椒素的受体，又作为有害热刺激的转导分子发挥作用。为了确定该蛋白的表达和定位，我们制备了针对VR1氨基末端和羧基末端的抗血清。在大鼠的背根神经节和三叉神经节内，VR1免疫反应性（VR1-ir）仅限于中小型神经元。VR1-ir被转运到这些初级传入神经元的中枢和外周突中，证据如下：（i）在浅背角I层和II层的神经纤维和终末中存在VR1-ir，以及VR1-ir与皮肤和角膜中的小直径神经纤维相关联；（ii）背根切断术后脊髓中VR1-ir减少；（iii）坐骨神经结扎近端VR1-ir的积累。在超微结构水平上，VR1-ir与背根神经节中神经元胞体的质膜以及背角中的神经终末相关联。在三叉神经脊髓核和孤束核的神经纤维和终末中也可见VR1-ir。在大部分背根神经节神经元及其轴突终末内，VR1-ir与P2X3嘌呤受体的染色以及凝集素IB4的结合位点共定位。令人惊讶的是，VR1-ir在含有P物质和降钙素基因相关肽的神经纤维和终末中基本不共存，这表明在应用辣椒素后这些神经肽释放的复杂机制。
