一氧化氮对致敏大鼠气道炎症及淋巴细胞功能的影响

探讨内源性一氧化氮与支气和哮喘气道症以及淋巴细胞免疫调节的作用。方法 应用鸡卵清蛋白腹腔致敏和反复超声雾化吸入刺激复制大鼠地敏性气道炎症模型。随机分为正常对照组；阳性对照组给予ＯＶＡ致敏，但不用Ｎ＾ω－硝在左旋精氨酸甲酯或左旋精氨酸，以生理盐水代之；用药组，每天给予ＯＶＡ雾化前分别给予３００ｍｇ／ｋｇ的Ｌ－ａｒｇ或３０ｍｇ／ｋｇ的Ｌ－ＮＡＭＥ腹腔注射。

Effects of nitric oxide on the airway inflammation and lymphocyte proliferation in sensitized rats

OBJECTIVE: To investigate the relations between intrinsic nitric oxide (NO) and airway inflammation and lymphocyte proliferation in bronchial asthma. METHOD: The rat model of asthmatic airway inflammation was established by first sensitizing and then challenging the animals with ovalbumin. NO synthase (NOS) inhibitor and NO precursor were then applied and their influences on the airway inflammatory cell numbers and on the numbers of mIL-2R positive lymphocytes were observed. RESULT: In vivo experiments showed that normal control rats (n = 6) did not have eosinophils in their submucosal of airways while in the sensitized animals (n = 6) eosinophils 23 +/- 5 (average cell counts per microscopic visual field, the same below) as well as lymphocytes (34 +/- 5) and mIL-2R positive cells (12 +/- 3) were found in significantly increased numbers in the airways. The application of NOS inhibitor significantly reduced eosinophils (13 + 3, P < 0.05) and mIL-2R positive cells (4.3 +/- 1.6, P < 0.05) in the sensitized animals and the number of lymphocytes was also decreased (28 +/- 4) although it did not reach the significant level. At the same time the spleen cell proliferation was inhibited (P < 0.05) and the mIL-2R positive spleen cell numbers were reduced (P < 0.05). On the contrary, the application of NO precursor resulted in the further increase of the numbers of eosinophils, lymphocytes and mIL-2R positive cells although the differences were not statistically significant. In vitro experiments showed that NOS inhibitor inhibited the proliferation of cultured spleen lymphocytes as well as their mIL-2R expression (P < 0.05). NO precursor, when used in low dose, could promote the proliferation and mIL-2R expression of spleen cells (P < 0.05); but high dose of it showed inhibiting effect on the spleen cells (P < 0.05). CONCLUSION: Intrinsic NO at a suitable level is important in the regulation of the proliferation and activation of lymphocytes in the airways with allergic inflammation in the sensitized rats. This research is conducive to the understanding of the pathogenesis of the asthmatic airway inflammation and to investigating of new therapeutic approaches.