糖皮质激素对肺泡巨噬细胞趋化活性的影响

采用测定肺泡巨噬细胞(AM)趋化性和AM产生中性粒细胞趋化因子的实验技术。观察到糖皮质激素体外直接作用于大鼠AM悬液或大鼠皮下注射7d都可抑制AM的趋化性,并且肺灌洗液中的AM数量明显减少;但注射3d组无上述效应。以糖皮质激素处理AM 16h可使AM产生的中性粒细胞趋化因子强度明显降低。结果表明糖皮质激素可抑制AM的趋化性和抑制AM产生中性粒细胞趋化因子。提示这可能是较长期应用糖皮质激素抑制免疫和炎症反应、降低肺部防御能力的部分机理。

EFFECT OF GLUCOCORTICOID ON CHEMOTACTIC ACTIVITIES OF ALVEOLAR MACROPHAGE

Using methods for measuring alveolar macrophage (AM) chemotaxis and AM-derived neutrophil chemotactic factor, it was observed that the chemotaxis of rat AM was inhibited by treatment with glucocorticoid in vitro or in vivo by subcutaneous injection for 7 consecutive days. The number of AMs in bronchoalveolar lavage fluid also markedly decreased (P<0.01). In contrast, no effect of glucocorticoid was seen in the groups receiving injection for 3 days. The AM-derived neutrophil chemotactic factor in AMs treated with glucocorticoid for 16h was markedly decreased (P<0.05). The results indicate that glucocorticoid can inhibit the AM chemotaxis and production of AM-derived neutrophil chemotactic factor. These may be the possible mechanism of immunosuppressive and inflammatory reactions and reduction of the defensive ability of lung after administration of glucocorticoid for a long time.