孤啡肽和内吗啡肽在神经源性痛模型大鼠疼痛相关脑区的改变

目的:检测孤啡肽(nociceptin/orphanin FQ, OFQ)和内吗啡肽(endomorphins, EM)在神经源性痛模型大鼠疼痛相关脑区杏仁核、下丘脑、导水管中央灰质(PAG)和纹状体的含量变化, 以假手术大鼠为对照.方法:利用大鼠L5/L6脊神经结扎神经源性痛模型,采用放射免疫的方法,检测OFQ和内吗啡肽在疼痛相关脑区的变化.结果:发现在下列脑区发生了显著变化:(1) 内吗啡肽1( EM1 )含量在神经源性痛大鼠下丘脑较对照鼠增加了38%, 纹状体降低了41%, 而在杏仁核和PAG与对照大鼠差异无显著性. (2) 内吗啡肽2( EM2 )含量在神经源性痛大鼠PAG较对照大鼠增加了778%, 在纹状体降低了43%,而在杏仁核和下丘脑与对照大鼠差异无显著性.(3) OFQ含量在在神经源性痛大鼠的杏仁核比对照大鼠增加了841%,在PAG比对照大鼠增加了459%;而在下丘脑和纹状体与对照大鼠差异无显著性.结论:神经源性痛引起中枢神经系统疼痛相关脑区EM1、EM2和OFQ的含量发生改变.

Changes of brain content of orphanin FQ and endomorphins in a rat model of neuropathic pain

Objective: To detect the change of brain content of orphanin FQ (OFQ) and endomorphins (EM) in nociception related brain areas (amygdala, hypothalamus, periaqueductal gray and striatum) of neuropathic pain rats, using sham operated rats as control.Methods: Neuropathic pain model was made by L 5/L 6 spinal nerve ligation, the immunoreacitivity (ir) of OFQ and EM was measured by radioimmunoassay (RIA). Results:(1) The content of EM1 ir of neuropathic pain rats showed a significant increase (38%) in hypothalamus, and a significant decrease (41%) in striatum, compared with the control group. (2) A parallel change of the content of EM2 ir was observed in PAG (+778%) and in striatum (-43%), no significant change in amygdala and hypothalamus. (3) A significant increase of the content of OFQ ir was found in amygdala (+841%) and PAG (+459%) respectively in neuropathic pain rats, but no significant change in hypothalamus and striatum. Conclusion: Neuropathic pain induced significant changes of the content of EM1,EM2 and OFQ ir in some nociception related brain areas.