Studies in~a new pain control by spinorphin, an endogenous factor : Changes in level of spinorphin and dipeptidyl peptidase III in cerebrospinal fluid from patients with pain

Spinorphin（LVVYPWT）是一种从脊髓中纯化的内源性生物活性肽，对缓激肽诱导的大鼠疼痛具有伤害性作用，对角叉菜胶诱导的小鼠急性炎症模型中性粒细胞聚集具有抑制活性。为了进一步阐明Spinorphin在疼痛和炎症中的生理作用，我们建立了人脑脊液（CSE）中Spinorphin的定量方法，并分析了其水平与生理状态之间的关系。首先，建立了特异、灵敏的竞争性酶免疫分析法（EIA）。特异性抗体与spinorphin类似物的交叉反应性不显著，表明EIA对spinorphin具有特异性。其次，在来自除癌痛以外的各种类型疼痛患者的CSF中测量的Spinorphin水平在疼痛组中高于对照组（患有无痛和非炎性中枢神经系统疾病的患者）（21.4± 8.2ng/ml，n=48 vs 8.61± 4.4ng/ml，n=28，P<0.05）。此外，研究了调节某些类型疼痛的几种Spinorphin加工酶的活性。疼痛组CSF中二肽基肽酶Ⅲ（DPPIII）活性低于对照组（1.40± 0.65vs2.05 ± 0.88pmol/30 min/100μ l，P<0.05）。Spinorphin水平的升高与DPPIII水平的降低呈显著相关（r=-0.514，P <$0.05）。这些结果表明，spinorphin的水平，通过酶的调节作用，可能是一个指标的病理生理状态。

Spinorphin (LVVYPWT), an endogenous bioactive peptide purified from the spinal cord, demonstrates a nociceptive effect on bradykinin-induced pain in the rat and inhibitory activity against carrageenan-induced neutrophil accumulation in the mouse model of acute inflammation. To further clarify its physiological role in pain and inflammation, we established a method to quantify spinorphin in human cerebrospinal fluid (CSE) and analyzed the relation between its level and the physiological state. First, a specific and sensitive competitive enzyme immunoassay (EIA) was developed with an anti-rabbit spinorphin antibody. Cross-reactivity of the specific antibody with spinorphin analogues was not significant, suggesting that the EIA was specific to spinorphin. Next, levels of spinorphin measured in CSFs derived from patients with various types of pain other than cancer pain were higher in the pain group than in the controls (patients with pain-free and noninflammatory disease of the central nervous system) (21.4±8.2 ng/ml, n=48 vs 8.61±4.4 ng/ml, n=28,P<0.05). Furthermore, the activity of several spinorphin-processing enzymes that regulate some types of pain was examined. The activity of dipeptidyl peptidase III (DPPIII) in CSFs of the pain group was lower than that in the control (1.40±0.65 vs 2.05±0.88 pmol/30 min/100μ1,P<0.05). Interestingly, a statistical correlation was observed between the increase of spinorphin levels and the decrease of DPPIII (r=-0.514,P<0.05). These results indicate that the level of spinorphin may, through the regulatory effect of enzymes, be an indicator of the pathophysiological state.