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.