单发佐剂性关节炎大鼠脊髓3种神经肽的变化规律

目的:观察慢性佐剂性关节炎大鼠脊髓3种神经肽含量及释放量的动态变化,以阐明其与炎症痛的关系.方法:采用完全弗氏佐剂在大鼠右后肢造成单发性关节炎模型,用放射免疫分析法检测致炎前及致炎后1～9周大鼠脊髓背半侧和脊髓灌流液中与疼痛有关的神经肽:八肽胆囊收缩素(cholecystokinin octapeptid,CCK-8)、孤啡肽(orphanin FQ,OFQ)、内吗啡肽-2(endornorphin-2,EM-2)的含量及释放量的动态变化.结果:(1)炎症期间,脊髓中CCK-8-ir释放量显著降低,脊髓背半侧含量于炎症第2周呈一过性增高;(2)OFQ-ir释放量于炎症后的第3、7周明显升高,而含量则在3周后降至正常水平以下,并以患侧变化更为明显;(3)EM-2-ir释放量于第1～2周明显降低,此后恢复正常,患侧脊髓含量1～9周均显著降低.结论:单发佐剂性关节炎大鼠脊髓背角和脊髓灌流液中有关的神经肽CCK-8、OFQ、EM-2均发生了可塑性变化.

Changes of three neuropeptides of the spinal cord in rats with adjuvant monoarthritis

Objective: To examine the changes of spinal immunoreactive (ir) cholecystokinin octapeptide (CCK 8), orphanin FQ (OFQ), endomorphin 2 (EM 2) in monoarthritic rats, and to explore the possible central neurochemical mechanisms of chronic pain. Methods: Monoarthritic rat model was produced by injection of water in oil complete Freund's adjuvant (CFA) into the right tibio tarsal joint and four neuropeptides in the spinal cord before and during 1 9 weeks of CFA injection were measured by radioimmunoassay. Results: (1) Marked decrease of CCK 8 ir in spinal perfusate was observed in full courses, but increase of CCK 8 ir content in dorsal spinal cord was observed only the second week after CFA injection. (2) The release of OFQ ir was significantly increased in the third and seventh weeks, whereas, the content decreased in the third week. More significant changes were observed in ipsilateral than contralateral dorsal spinal cord. (3) The level of EM 2 ir in spinal perfusate decreased in the first week, then recovered to the normal level since the third week. The content of EM 2 ir was significantly lower than that of the control. Conclusion: Plastic changes occurred in the spontaneous release and the content of dorsal spinal cord in CCK 8 ir, OFQ ir, EM 2 ir with adjuvant induced monoarthritis.