中性粒细胞弹性蛋白酶和IL-8在大鼠哮喘中的作用及地塞米松调控

目的 观察中性粒细胞弹性蛋白酶（NE）和IL-8在大鼠哮喘中的作用及地塞米松（DM）对其功能的影响.方法 采用大鼠哮喘模型,随机分成哮喘组（A组）、正常对照组（B组）、地塞米松治疗组（C组）,对周围血内中性粒细胞（PMN）进行分离纯化,ELJSA法检测血PMN和支气管肺泡灌洗液（BALF）中NE和IL-8的表达水平.结果 A组血PMN和BALF中NE、IL-8表达水平均显著高于B组（P＜0.01）,C组均显著低于A组（P＜0.01）.C组血PMN中NE的表达水平显著高于B组（p＜0.05）,而BALF中则无显著性差异（P＞0.05）.C组血PMN和BALF中IL-8的表达水平与B组相比差异均无统计学意义（P＞0.05）.BALF和肺组织中PMN计数A组显著高于B组（P＜0.01）,肺组织中PMN计数C组显著高于A组（P＜0.01）,而两组BALF中PMN占细胞总数的百分比差异无统计学意义（P＞0.05）.BALF中PMN计数和IL-8呈显著正相关（P＜0.05）.结论 PMN、NE和IL-8参与了哮喘的炎症过程,PMN可能通过合成IL-8、NE起作用,其合成功能可以被地塞米松所抑制.IL-8与PMN在BALF中浸润密切相关.

The function of neutrophil elastase, IL-8 and regulation of dexamethasone in rat asthma

Objective To identify the functions of neutrophil elastase (NE) and IL-8, and the effect of dexamethasone in rat asthma. Methods The rat model of asthma were randomly divided into three groups on average, including asthma group(group A), control group(group B) and dexamethasone treated group(group C). The protein concentration of NE and IL-8 were detected by ELISA in bronchoalveolar lavage fluid(BALF) and blood PMN. The correlation of PMN and IL-8 were analyzed in BALF. Results Level of NE and IL-8 was significantly increased in group A than group B(P<0.01), and significantly decreased in group C than group A(P< 0.01). In group C, level of NE in PMN was significantly increased than that in group B(P<0.05), while there was no significant difference in BALF(P>0.05). Level of IL-8 was not significant different in PMN and BALF(P>0.05). The number of PMN was significantly increased in group A than group B in BALF and lung tissue(P<0.01), and in lung tissue they were significantly increased in group C than group A (P< 0.01), but the percentage of PMN was not significantly different in BALF in group C as compared to group A. Conclusion PMN, NE and IL-8 are involved in inflammation of asthma. PMN may increase the synthesis of NE and IL-8, but this function of PMN can be inhibited by dexamethasone. IL-8 is correlated with PMN infiltration in BALF.