Oxidative stress in cotton smoke inhalation-induced acute lung injury in rats

Abstract

Objective To investigate the mechanisms of oxidative stress in cotton smoke inhalationinduced acute lung injury in rats. Methods Eighteen male SD rats were randomly divided into control group,6 h group,and 24 h group.The rat model of cotton smoke inhalation injury was established.After smoke inhalation rats were mercy killed.The concentrations of malondialdehyde(MDA),glutathione (GSH),nitric oxide(NO),inducible nitric oxide synthase(iNOS),andγ-glutamyl systeine synthetase (γ-GCS) in homogenized lung tissue were measured by enzyme-linked immunosorbent assay and the relative expressions of iNOS mRNA andγ-GCS m RNA were detected by fluorescence quantitative PCR. Results Compared with the control group,concentrations of MDA, NO,iNOS,γ-GCS and relative expressions of iNOS m RNA andγ-GCS m RNA in homogenized lung tissue in 6 h group and 24 h group were significantly elevated(all P< 0.05),moreover,concentration of NO and relative expressions of iNOS mRNA andγ-GCS mRNA in 24 h group were higher than those in 6 h group(all P< 0.05).The concentration of GSH in homogenized lung tissue in 6 h group was lower than that in control group,but higher than that in 24 h group. Conclusions Oxidative stress significantly enhances in rats with cotton smoke inhalation-induced acute lung injury,meanwhile,the activation of antioxidative system is not enough.As a result,the oxidative-antioxidative balance is disturbed and lung injury becomes worse. Key words: Acute lung injury; Smoke inhalation injury; Oxidative stress