硫化氢在大鼠急性支气管哮喘模型中的变化及意义

目的观察卵白蛋白（OVA）诱导的大鼠急性支气管哮喘（简称哮喘）模型，内源性硫化氢（H2S）生成的变化以及应用外源性硫氢化钠（NaHS，H2S供体）处理对哮喘大鼠的影响，探讨气体信号分子H2S在哮喘发病中的作用。方法24只健康SD大鼠按随机数字表法分为正常对照组、哮喘组和NaHS干预组，每组8只。致敏后28d测定所有大鼠肺功能并观察大鼠支气管周围炎性细胞浸润程度并进行评分；采用敏感硫电极测定血浆及肺组织H2S的生成量；采用酶促反应法测定大鼠肺组织匀浆中胱硫醚-γ-裂解酶（CSE）活性；用Western blot法测定大鼠肺组织中CSE蛋白含量（每组3只）。结果哮喘组大鼠呼气峰流量（PEF）、血浆及肺组织中H2S分别为（2．90±0．70）L／s、（10±3）、（4．9±1．3）μmoL／L，对照组分别为（6．50±0．10）L／s、（54±10）、（24．1±8．0）μmoL／L，NaHS干预组大鼠分别为（5．70±0．50）L／s、（17±4）、（15．3±4．0）μmol／L，3组间比较差异有统计学意义（F值分别为112．13、110．10、27．34，P均〈0．01）；哮喘组大鼠肺组织匀浆每毫克蛋白中CSE活性和肺组织匀浆中CSE蛋白含量[用相对吸光度（A）值表示]分别为（1．00±0．10）nmol·min^-1·mg^-1、0．20±0．10，正常对照组分别为（1．80±0．10）nmo]·min^-1·mg^-1、0．90±0．30，NaHS干预组大鼠分别为（1．60±0．20）nmo]·min^-1·mg^-1、1．10±0．20，3组间比较差异有统计学意义（F值分别为79．39、12．28，P均〈0．05）；光镜下支气管周围炎性细胞浸润程度评分[用中位数（四分位数）]表示，正常对照组为1（0～1）分，哮喘组为3（2～4）分，NaHS干预组为1（1～2）分，3组间比较差异有统计学意义（H=16．93，P〈0．01）；哮喘组肺组织H2S含量与PEF呈正相关（r=0．74，P〈0．01）；与光镜下支气管周围炎性细胞浸润程度评分呈负相关（r=-0．64，P〈0．01）。结论内源性H2S参与了大鼠急性哮喘发病过程，外源性NaHS可以减轻哮喘气道炎症，对哮喘急性发病起到保护作用。

The regulatory effect of endogenous hydrogen sulfide on acute asthma

OBJECTIVE: To study the changes of endogenous hydrogen sulfide (H(2)S) and the effect of exogenously applied H(2)S on ovalbumin-induced acute asthma. METHODS: Twenty-four Male SD rats were randomly divided into a control group (n = 8), an asthma group (n = 8) and a NaHS group (n = 8). Pulmonary function was measured, and the pulmonary pathology changes, the content of H(2)S in lung tissue and plasma and the activity of H(2)S generating enzymes in lung tissue were detected at the 28 th day after ovalbumin administration. Western blotting was used to detect the endothelial cystathionine-gamma-lyase CSE protein in the lung tissues. RESULTS: In the asthma group, the peak expiratory flow (PEF) was (2.90 +/- 0.70) L/s, the contents of H(2)S in the plasma was (10 +/- 3) micromol/L, in the lung tissue was (4.9 +/- 1.3) micromol/L. The H(2)S generating enzyme activity in the lung tissue of the asthma group was (1.00 +/- 0.10) nmolxmin(-1)xmg(-1) pro, and the lung CSE content of the asthma group was significantly lower than that of the control group (6.50 +/- 0.10) L/s, (54 +/- 10), (24.1 +/- 8.0) micromol/L, (1.80 +/- 0.10) nmolxmin(-1)xmg(-1), F = 112.13, 110.10, 27.34, 79.39, 12.28, all P < 0.05). The pulmonary pathology score of the asthma group was 3 (2 - 4), significantly higher than that of the control group [1 (0 - 1), H = 16.93, P < 0.01]. In the NaHS group, the PEF was (5.70 +/- 0.50) L/s, the content of H(2)S in the plasma was (17 +/- 4) micromol/L, in the lung tissue was (15.3 +/- 4.0) micromol/L, the H(2)S generating enzyme activity in the lung tissue was (1.60 +/- 0.20) nmolxmin(-1)xmg(-1) pro, the lung CSE content of the NaHS group was significantly higher than that of the asthma group (F = 112.13, 110.10, 27.34, 79.39, 12.28, all P < 0.05). The pulmonary pathology score of the NaHS group was 1 (1 - 2), significantly lower than that of the asthma group [3 (2 - 4) score, H = 16.93, P < 0.01]. There was a significantly positive correlation between the content of the content of H(2)S in lung tissue and PEF (r = 0.74, P < 0.01). There was a significantly negative correlation between the content of H(2)S in lung tissue and the pulmonary pathology score (r = -0.64, P < 0.01). CONCLUSION: Endogenous H(2)S is involved in the pathogenesis of asthma in this animal model. Exogenously applied H(2)S can attenuate inflammation of asthma and exert protective effect from asthma.