Vanilloid (capsaicin) receptors in the rat: distribution in the brain, regional differences in the spinal cord, axonal transport to the periphery, and depletion by systemic vanilloid treatment
Vanilloid (capsaicin) receptors in the rat: distribution in the brain, regional differences in the spinal cord, axonal transport to the periphery, and depletion by systemic vanilloid treatment
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DOI：
10.1016/0006-8993(95)01094-7
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发表时间：
1995-12
期刊：
影响因子：
2.9
通讯作者：
A. Szallasi;S. Nilsson;T. Farkas-Szallasi;P. Blumberg;T. Hökfelt;J. Lundberg
中科院分区：
文献类型：
--
作者：
A. Szallasi;S. Nilsson;T. Farkas-Szallasi;P. Blumberg;T. Hökfelt;J. Lundberg
香草素（辣椒素）受体可视化[3 H]树脂毒素（RTX）放射自显影在新生儿以及成年（对照组和秋水仙素治疗）大鼠的大脑。特异性标记仅见于脑干、延伸至最后区的孤束核和三叉神经脊感觉核。在背角、背根、三叉神经节和结状神经节也可见强信号。从脊髓的颈段、胸段和腰段获得的膜显示出对RTX的相似亲和力，同样对辣椒素和辣椒平的相似亲和力;最大受体密度在颈段和胸段中相似（约70 fmol/mg蛋白质），但在腰段中是其两倍高。结扎迷走神经或坐骨神经后24 h，观察到特异性RTX结合位点的强烈积累，主要在结扎近端，这意味着轴突内受体分别从结状神经节和背根神经节转运到外周。全身（s.c.）香草素处理耗尽了来自脑干、感觉（背根以及三叉神经）神经节和脊髓的特异性[3 H]RTX结合位点。RTX从脊髓中清除香草素受体的效力比辣椒素强约200倍。目前的结果表明，在脑干（感觉核）的香草素受体的离散表达，虽然内在的香草素受体表达神经元被认为是存在于大鼠大脑中，他们仍然未检测到目前的[3 H]RTX放射自显影方法。
Vanilloid (capsaicin) receptors were visualized by [3H]resiniferatoxin (RTX) autoradiography in the brain of newborn as well as adult (both control and colchicine-treated) rats. Specific labelling was seen in the brain stem only, in the nucleus of the solitary tract extending into the area postrema and the spinal sensory nucleus of the trigeminal nerve. Also, a strong signal was seen in the dorsal horn, dorsal root, trigeminal and nodose ganglia. Membranes obtained from the cervical, thoracic, and lumbar segments of the spinal cord showed similar affinities for RTX and likewise for capsaicin and capsazepine; maximal receptor density was similar in the cervical and thoracic segments (approximately 70 fmol/mg protein) but was twice as high in the lumbar segment. 24 h after ligation of the vagal or the sciatic nerves, a strong accumulation of specific RTX binding sites was observed mainly proximal to the ligature, implying intraaxonal receptor transport from the nodose and dorsal root ganglia, respectively, to the periphery. Systemic (s.c.) vanilloid treatment depleted specific [3H]RTX binding sites from the brain stem, the sensory (dorsal root as well as trigeminal) ganglia, and the spinal cord. RTX was approximately 200-fold more potent than capsaicin for eliminating vanilloid receptors from the spinal cord. The present results suggest a discrete expression of vanilloid receptors in the brain stem (sensory nuclei); although intrinsic vanilloid receptor-expressing neurons are thought to exist in the rat brain, they remain undetected by the present [3H]RTX autoradiography methodology.