P物质和一氧化氮在致BALB/c小鼠变应性接触性皮炎模型瘙痒中的作用

Role of Substance P and Nitric Oxide in Pathogenesis of Itch in BALB/c Mice With Allergic Contact Dermatitis

目的：探讨P物质（SP）和一氧化氮（NO）在BALB/c小鼠变应性接触性皮炎（ACD）模型瘙痒中的作用。方法：外用2,4-二硝基氟苯（DNFB）建立BALB/c小鼠ACD模型,观察激发后97 h内小鼠的搔抓行为及NK1受体拮抗剂spantide、L-精氨酸和一氧化氮合酶抑制剂（L-NAME、7-硝基吲唑、氨基胍）对小鼠搔抓行为的影响,并用硝酸还原酶法检测激发后0~1 h、36~37 h小鼠颈背部皮肤中NO含量。结果：ACD小鼠在激发后0~1 h出现1次搔抓高峰,搔抓次数明显多于对照组（P〈0.01）。除提前10 min皮内注射L-精氨酸可明显增强激发后84~85 h的小鼠搔抓行为（P〈0.05）外,spantide、L-NAME、7-硝基吲唑或氨基胍预处理对小鼠各时点搔抓行为均无明显影响（P〉0.05）。ACD小鼠皮损中NO含量在激发后0~1 h明显低于对照组（P〈0.01）。结论：ACD小鼠搔抓时程与迟发型变态反应过程相似。SP和NO在DNFB诱导的BALB/c小鼠ACD模型瘙痒中可能不起主要作用。

Objective：To investigate the role of substance P（SP） and nitric oxide（NO） in the pathogenesis of itch in BALB/c mice with allergic contact dermatitis（ACD）. Methods：BALB/c mice with ACD were established by topical application of 2,4-dinitrofluorobenzene（DNFB）.The scratching behavior and the effect of spantide（NK1 receptor antagonist）,L-arginine,and nitric oxide synthase inhibitors（L-NAME,7-nitroinzadole and aminoguanidine） were observed within 97 h after challenge.NO concentration of skin lesion on the nape was measured by nitrate reductase method at 0-1 h and 36-37 h after challenge.Results：The scratching response of ACD mice peaked at 0-1 h after challenge,and its total number of scratching bouts was superior to that in 3 control groups（P0.01）.Spantide,L-NAME,7-nitroinzadole or aminoguanidine pretreatment had no effect on the scratching frequency in ACD mice at all time points after challenge（P0.05） though pretreatment with L-arginine at 10 min before challenge significantly augmented the scratching behavior at 84-85 h（P0.05）.NO level of skin lesion in ACD mice at 0-1 h after challenge was obviously lower than that in control group（P0.01）.Conclusion：The scratching time-course in ACD mice is similar to that of the delayed type of allergic response.SP and NO should play a little role in the pathogenesis of itch in BALB/c mice with ACD.