Sharma H S, Nyberg F, Thörnwall M, Olsson Y
Department of Pharmacology, University of Uppsala, Sweden.
Neuropharmacology. 1993 Jul;32(7):711-7. doi: 10.1016/0028-3908(93)90085-h.
The possibility that trauma to the dorsal horn may affect the release and distribution of enkephalin was examined using the opioid peptide Met-Enk-Arg6-Phe7 (MEAP) as a marker in a rat model. The peptide content of samples of spinal cord and whole brain was measured using a radioimmunoassay (RIA) technique. In addition, the possible functional relation between this peptide and serotonin was evaluated using a pharmacological approach that included depletion of endogenous serotonin. A focal trauma to the right dorsal horn in the T10-11 segments (2 mm deep and 5 mm long) markedly modified the content of MEAP of the adjacent rostral and caudal segments of the cord, as well as the content of MEAP of the brain. Depletion of serotonin with p-CPA (an inhibitor of the synthesis of serotonin) significantly elevated the content of MEAP in the whole brain without affecting the regions of the spinal cord (except T9 level which showed a 25% decrease from an intact control group). Trauma to the spinal cord in the serotonin-depleted animals did not alter the content of MEAP further, as compared to a p-CPA-treated but untraumatized group. These results indicate that enkephalin (i) participates in the pathophysiology of spinal cord trauma and (ii) suggest that the peptide is somehow functionally related with serotonin.
在大鼠模型中，以阿片肽甲硫氨酸脑啡肽-精氨酸6-苯丙氨酸7（MEAP）作为标志物，研究了背角损伤可能对脑啡肽释放和分布产生的影响。采用放射免疫分析（RIA）技术测定脊髓和全脑样本中的肽含量。此外，采用包括耗尽内源性5-羟色胺在内的药理学方法，评估了该肽与5-羟色胺之间可能的功能关系。在T10-11节段对右侧背角进行局部损伤（深2mm，长5mm），显著改变了脊髓相邻头侧和尾侧节段以及脑中MEAP的含量。用对氯苯丙氨酸（一种5-羟色胺合成抑制剂）耗尽5-羟色胺，可显著提高全脑中MEAP的含量，但不影响脊髓区域（除T9水平，与完整对照组相比下降了25%）。与经对氯苯丙氨酸处理但未受损伤的组相比，5-羟色胺耗尽动物的脊髓损伤并未进一步改变MEAP的含量。这些结果表明，脑啡肽（i）参与脊髓损伤的病理生理学过程，（ii）提示该肽在某种程度上与5-羟色胺存在功能关系。
