Heme oxygenase-1 regulates oxidant and antioxidant imbalance in guinea pigs with asthma

Abstract

Objective To explor the antioxidant effects of heme oxygenase-1 （ HO-1 ） for asthma and its mechanism. Methods Thirty two months old healthy male guinea pigs were randomly assigned to 3 groups, all of them were feed under the same management condition. Asthmatic group, refering to Huston＇s research results, were sensitized by exposure to aerosolized ovalbumin（OVA） in order to build the guinea pig motile of asthma. Dexamethasone group （ DG）, were also sensitized by exposur to aerosolized ovalbumin as well as the asthraatic group had done and then treated with dexamethasone. Normal control group （NCG） ： were treated with 0. 9% sterile sodium chloride. All the tested animals were measured the activity of lung HO-1 ,levels of malondialdehyde （MDA） in the lung tissue or serum and bilirubin in the serum by spectro photometry. And the pathology and expression of HO-lprotein in the lung tissue were observed. Results In the OVA induced asthmatic group ,the HO-1 activity and level of MDA in lung tissue or serum were markedly increased compared with the groups of NCG and DG （ P 〈0. 01 ） and the expression of lung HO-1 protein was as 3-4 grade. While level of b＇llirubin was markedly reduced compared with NCG and DG. For example,in asthmatic group,the activity of lung HO-1 was,the level of bilirubin formed,（901.12 ＋321.53） pmol/（mg protein.h）. The level of MDA in senma was（ 12. 25 ＋2. 49） mmoL/ml. The level of lung MDA was（69. 38 ＋ 7. 49） nmol/mg protein,and the level of bilimbin in serum was （0. 54 ＋_0.23 ） pmol/L. In DG,the data of HO-1 and MDA as described above were markedly reduced compared with the OVA induced asthmatic group（P 〈0. 01 ） ,and lung pro- tein expression was 1-2 grade,while the level of bilirubin in the serum was increased（P 〈 0. 01 ）. But,all datas of DG had no significant difference compared with NCG （ P 〉 0. 05 ）. Conclusion The guinea pigs＇ in vivo lipid peroxide level increases and the level of bilirubin, an antioxidant, markedly decrease during asthma attacks, which induce the imbalance of oxidant and antioxidant. Content level and activity of HO-1 protein can in crease in asthma body in order to compensate the reduce of bilirubin level, regulate the imbalance of oxidant and antioxidant, protect lung tissues from oxidizing reaction damage and relieve allergy or asthma symptoms. Key words: Heme oxygenase-I ; Bilirubin; Asthma; Oxidation; Malondialdehyde; Guinea pigs