脊髓后角P物质在实验性自身免疫病发病中的作用

在实验性过敏性神经炎（ＥＡＮ）、实验性过敏性脑脊髓炎（ＥＡＥ）及佐剂性关节炎（ＡＡ）３种不同自身免疫病动物模型上，观察改变脊髓后角（ＳＤＨ）Ｐ物质（ＳＰ）水平对免疫功能及自身免疫病（ＩＤ）发病的影响。结果表明以辣椒素（Ｃａｐ）耗竭ＳＤＨＳＰ或脊髓蛛网膜下腔注射（ｉｔｈ）ＳＰ受体拮抗剂均可使机体免疫反应亢进，ＩＤ发病率上升、发病潜伏期缩短、病情加重；相反ｉｔｈＳＰ受体激动剂可使机体免疫功能抑制，ＩＤ病情减轻。３种动物模型在发病高峰期ＳＤＨＳＰ含量均显著上升。提示ＳＤＨＳＰ参与ＩＤ的发病过程；在免疫应答高峰期ＳＤＨＳＰ含量的升高可经某种途径反馈性地抑制免疫反应，使后者不致过强。ＳＰ在免疫负反馈调节中起神经递质的作用，故提高ＳＤＨＳＰ水平对ＩＤ治疗可能有益。

The Role of Substance P in the Spinal Dorsal Horn in the Pathogenesis of Autoimmune Diseases

The aim of the present study is to explore the role of immunosupression mediated by substance P(SP)in spinal dorsal horn(SDH) in the pathogenesis of the autoimmune dideases.The experimental allergic neuritis(EAN),experimental allergic encephalomyelitis(EAE)and adjuvant arthritis(AA)animal models were established in the guinea pigs and Wistar rats, respectively.The effects of alteration of SP activity in SDH on immune responses and the pathogenesis of the autoimmune diseases were observed.The results showed that decreasing activity of SP in SDH by pretreatment of capsaicin or intrathecal SP antagonist could enhance cellular and humoral immune responses and aggravate the autoimmune diseases,while intrathecal SP agonist could supress the immunity and alleviate clinical signs.The contents of SP in SDH was elevated dramatically at the peak of immune responses.These results suggest that SDH SP might participate in the pathogenesis of the autoimmune diseases.The increase of SP contents in SDH may inhibit the immune system via unknow pathway and ease clinical severity of the autoimmune disease,where SP might act as neurotransmitter in the immunoregulation of the negative feedback.To elevate SP content in SDH might be benifical to the autoimmune diseases.