隐孔菌多糖成分对致敏大鼠气道高反应性和炎症细胞的影响

目的：研究隐孔茼多糖成分对大鼠气道高反应性的影响，初步探索其作用机制。方法：采用卵白蛋白致敏雾化吸入攻击制备大鼠哮喘模型，隐孔茼多糖成分A、B(5mg／kg、20mg／kg)和酮替芬(5mg／kg)及溶媒对照(等量生理盐水)灌胃10d。用甲酰胆碱激发气道高反应性后，行支气管肺泡灌洗和腹腔灌洗，计数支气管肺泡灌洗液中细胞总数并分类，和腹腔灌洗液中脱颗粒肥大细胞及白细胞分类。结果：隐孔菌多糖成分A、B均能明显抑制致敏大鼠抗原攻击后气道阻力的增加及肺顺应性的下降；减少支气管肺泡灌洗液中白细胞总数，降低嗜酸细胞的数目，以多糖B作用更明显；多糖A和多糖B也明显抑制腹腔肥大细胞脱颗粒及腹腔嗜酸性粒细胞的渗出。结论：隐孔菌多糖A、B成分抑制大鼠的气道高反应性，其作用可能与稳定肥大细胞膜、抑制嗜酸细胞炎症和趋化有关。

Effects of polysaccharides of Cryptoporus volvatus on bronchial hyperreasponsiveness and inflammatory cells in ovalbumin sensitized rats

Objective: To study the effects of polysaccharides of cultured Cryptoporus volvatus(CVPS) on airway hyperresponsiveness of ovalbumin-sensitized rats and to evaluate their mechanisms. Methods: Polysaccharides A,B(5 mg/kg,20 mg/kg) and ketotifen(5 mg/kg) or vehicle(same volume of saline) were administrated orally for 10 days in ovalbumin-sensitized rats,methacholine bronchial provocation tests were performed to determine airway hyperresponsiveness. Bronchoalveolar lavage fluid(BALF) and peritoneal lavage fluid were prepared after the animals were challenged by nebulized antigen. The differential white cell count in BALF,and the degranulated mast cell count as well as differential white cell count in peritoneal lavage fluid were performed. Results: Polysaccharides markedly inhibited the increased lung resistance and the decreased lung compliance induced by antigen challenge,significantly reduced total cell counts and absolute eosinophil counts in BALF(P<0.05); polysaccharides B was more effective than polysaccharides A. They also inhibited recruitment of inflammatory cells in peritoneal lavage fluid and inhibited the allergen-induced mast cell degranulation. Conclusion: Polysaccharides of CVPS inhibit airway hyperresponsiveness by stabilizing mast cell membranes and reducing infiltration and chemotaxis of eosinophils and may be developed as a potential anti-asthmatic drug.