布地奈德对哮喘小鼠TNOS、cNOS、iNOS及内皮素的影响

目的观察吸入布地奈德（budesonide，BUD）对小鼠哮喘模型哮喘发作、血清及支气管肺泡灌洗液（bronchoalveolar lavage fluid，BALF）中总的一氧化氮合酶（total nitric oxide synthase，TNOS）、结构型一氧化氮合酶（constitutive nitric oxide synthase，cNOS）、诱导型一氧化氮合酶（inducible nitric oxide synthase，iNOS）、内皮素（andothelin，ET）的影响，探讨BUD防治哮喘的机制。方法30只BALB／c小鼠随机分为3组：哮喘模型组（A组，n=10）、BUD治疗组（B组，n=10）、正常对照组（C组，n=10）。以卵蛋白（ovalbumin，OVA）致敏及激发建立小鼠哮喘模型，观察哮喘发作及肺组织病理情况。采用放射免疫法测定3组小鼠血清及BALF中TNOS、iNOS、cNOS的活性及ET-1的水平。结果B、C2组血清及BALF中TNOS、cNOS、iNOS活性及ET-1的水平均明显低于A组（P均〈0．01），B组TNOS、iNOS、cNOS的活性与C组比较差异均无统计学意义（P均〉O．05），而B组ET-1水平明显高于C组（P〈0．05），B、C2组BALF中WBC总数均明显低于A组（P均〈0．01），血清中iNOS活性与ET-1水平呈正相关（r=0．827，P〈0．01），BALF中iNOS活性与ET-1水平呈正相关（r=0．776，P〈0．01）。结论吸入布地奈德防治哮喘的机制可能与抑制哮喘小鼠BALF、血清中TNOS、iNOS、cNOS活性及ET-1水平有关。但并不完全，气道炎症一旦形成，可能需要较长时间来控制。

Effects of Budesonide on TNOS,iNOS,cNOS and Endotheoin in Mice with Allergic Asthma

Objective To observe the effects of budesonide on TNOS.iNOS. cNOS and endothelin in asthmatic mice and discuss the mechanism of the preventive and therapeutic effect of budesonide on the asthma1. Methods Thirty female BALB/c mice were randomly divided into three groups： asthmatic was group A （n=10）, Budesonide administration was group B（n=10）, normal saline control was group C（n=10）. Mice were sensitized and challenged with OVA to establish asthmatic mice models. Observed their asthmatic condition and the pathological condition of their bronchopulmonary tissue. The activity of TNOS, iNOS, cNOS and the levels of ET-1 in serum and BALF of growp A,B and C,were tested with radioimmunoassay. Results The levels of TNOS, iNOS,cNDS and ET-1 were significantly increased in group A, and were decreased in group B and C（all P〈0.01）. The activity of TNOS.iNOS. cNOS had no differences between groups B and C（all P〉0.05）,but the levels of ET-1 in group B is higher than the group C, respectively（P〈0.05）. The number of inflammatory cells in BALF of groups B and C were significantly decreased when compared with group A （all P〈0. 01）. A positive correlation was observed between iNOS and ET- 1 in the serum and BALF（r=0. 827,0. 776,all P〈0.01）. Conclusion The mechanism of BUD treat asthma may be related to down-regulation of expression of TNOS,iNOS,cNOS and ET-1 in serum and BALF. But the suppression may be imperfectly, and there is a long time to control the airway inflammation if once it is indeed.