HIGH-RESOLUTION AUTORADIOGRAPHIC LOCALIZATION OF [I-125] FK-33-824-LABELED MU-OPIOID RECEPTORS IN THE SPINAL-CORD OF NORMAL AND DEAFFERENTED RATS
HIGH-RESOLUTION AUTORADIOGRAPHIC LOCALIZATION OF [I-125] FK-33-824-LABELED MU-OPIOID RECEPTORS IN THE SPINAL-CORD OF NORMAL AND DEAFFERENTED RATS
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DOI：
10.1016/0306-4522(91)90427-p
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发表时间：
1991-01-01
期刊：
影响因子：
3.3
通讯作者：
QUIRION, R
中科院分区：
文献类型：
--
作者：
GOUARDERES, C;BEAUDET, A;QUIRION, R
最近的数据表明，[I-125] D-Ala 2，MePhe 4，Met（o）ol 5-脑啡肽（FK-33-824）是一种高选择性和特异性μ阿片受体配体[Moyse等（1986）Peptides 7，351-355]。 该探头用于研究脊髓不同节段mu位点的详细放射自显影分布。 在未处理和去传入大鼠的脊髓中，通过氚敏感胶片和液体乳剂放射自显影定位[I-125]FK-33-824结合位点。 在未处理动物中，高密度的mu位点在背角的所有水平的板层I-II内是明显的，与腰椎段中的IIo相比，在层IIi中观察到更高水平的标记。 层III-IV含有约一半的结合量观察到的浅层。 在上颈髓的第六层和整个Clarke氏柱也观察到相对高密度的部位。 在后者中，[I-125]FK-33-824的结合明显避免了脊髓小脑神经元的大胞体。 在腹角中，[I-125]FK-33-824结合主要集中在第IX层，在颈椎和腰椎增大的水平。 标记位点仅限于神经节，大多数保留运动神经元的索马体。在颈（C3-C7）或腰（L1-L 6）神经根切断术后4天，检测到I-125]FK-33-824在板层I-II（55%）和III-IV（28%）中的结合率显著降低。 这些下降在C3-C7节段损伤后7天最为明显（在板层I-II和III-IV中分别为93%和76%），此后直至损伤后28天略有恢复。 与此相反，背根切断术并没有影响亩标签无论是在腹角或克拉克的列。 这些结果证实了与背侧初级传入纤维的亩阿片类药物结合位点的协会，并证明存在的亩网站在克拉克的柱和板IX的腹角。这些研究结果表明，内源性阿片类药物在脊髓中发挥的作用，在感觉运动的整合，以及在调制的初级伤害性输入。
Recent data have shown that [I-125]D-Ala2, MePhe4, Met(o)ol5-enkephalin (FK-33-824) is a highly selective and specific mu opioid receptor ligand [Moyse et al. (1986) Peptides 7, 351-355]. This probe was used here to investigate the detailed radioautographic distribution of mu sites at various levels of the spinal cord. [I-125]FK-33-824 binding sites were localized by both tritium-sensitive film and liquid emulsion radioautography in the spinal cord of naive and deafferented rats. In naive animals, high densities of mu sites were apparent within laminae I-II at all levels of the dorsal horn, with higher levels of labelling seen in layer IIi as compared to IIo in the lumbar segment. Laminae III-IV contained about half the quantities of binding observed in superficial layers. Relatively high densities of sites were also seen over lamina VI in the upper cervical cord and throughout Clarke's column. Within the latter, [I-125]FK-33-824 binding clearly spared the large perikarya of the spinocerebellar neurons. In the ventral horn, [I-125]FK-33-824 binding was mainly concentrated in layer IX, at the level of cervical and lumbar enlargements. Labelled sites were confined to the neuropil, mostly sparing the soma of motoneurons.Significant decreases in [I-125]FK-33-824 binding in laminae I-II (55%) and III-IV (28%) were detected four days following cervical (C3-C7) or lumbar (L1-L6) rhizotomies. These decrements were most evident at seven days post-lesion at C3-C7 levels (93 and 76% in laminae I-II and III-IV, respectively) and recovered slightly thereafter up to 28 days post-lesion. In contrast, dorsal rhizotomies did not influence mu labelling in either the ventral horn or Clarke's column. These results confirm the association of mu opioid binding sites with dorsal primary afferent fibres and demonstrate the presence of mu sites in Clarke's column and lamina IX of the ventral horn.These findings suggest that endogenous opioids in the spinal cord play a role in sensory motor integration as well as in the modulation of primary nociceptive inputs.