支气管哮喘豚鼠肺内嗜酸粒细胞增多和凋亡的关系

目的　探讨支气管哮喘 (简称哮喘 )肺内嗜酸粒细胞 (Eos)增多与Eos凋亡的关系。方法　采用卵蛋白致敏的豚鼠哮喘模型 ,动态观察肺组织病理学、支气管肺泡灌洗液 (BALF)细胞学和Eos凋亡的变化。结果　致敏豚鼠抗原激发后 ,血管周围Eos迁移和浸润主要发生在 2 4h以内 ,而支气管周围Eos浸润和BALF内Eos增高持续 1周以上。哮喘豚鼠第 2 4,48,72hEos凋亡率分别为 (2 .1± 1.3 ) % ,(3 7± 2 3 ) % ,(4 6± 2 7) % ,显著低于正常豚鼠 [(10 .1±3 4) % ,P <0 .0 5 ] ,至 168h才接近于正常水平。糖皮质激素地塞米松治疗使Eos凋亡率显著增加 [(3 4 .1± 12 .2 ) % ,P<0 .0 1] ,伴随气道炎症消退。结论　哮喘Eos凋亡抑制可能是肺内Eos浸润增加的一个重要机制

Relationship between pulmonary airway eosinophil infiltration and apoptosis in allergic guinea pigs

Objective To investigate the relationship between pulmonary airway eosinophil accumulation and apoptosis in a guinea pig model of asthmatic response to ovalbumin inhalation. Methods We have made a detailed examination of histopathology, cytology and apoptosis in the airways up to 7 days after antigen challenge. Apoptosis of eosinophils was measured by using in situ tailing technique. We also observed the changes of eosinophils apoptosis in lung after treatment with dexamethasone. Results Eosinophil migration in bronchus was obvious from 8 h to 24 h following antigen challenge, then declined. Eosinophilia was demonstrable in bronchoalveolar lavage fluid (BALF) and bronchial tissue at 8 h, peaked during 24h to 72h and persisted for at least 7 days. Eosinophilia was accompanied by epithelial damage and subepithelial edema. The percentage of eosinophils apoptosis in BALF of allergic guinea pigs was (2.1±1.3)%, (3.7±2.3)%, and (4.6±2.7)% respectively at 24,48 and 72 h, significantly lower than that of normal control guinea pigs (P＜0.05). The percentage of eosinophils apoptosis significantly increased ［(34.1±12.2）%, P＜0.01］, accompanied by resolution of lung inflammation following treatment with dexamethasone. Conclusion The apoptosis of eosinophils in asthmatic guinea pigs was inhibited, contributing to persistent eosinophilia.