The Protective Effects Of Hydrogen-rich Saline On Smoke Inhalation-induced Acute Lung Injury

Objective:To discuss the therapeutical effect on smoke inhalation injury in rats with different doses of hydrogen-rich saline.Methods:30rats were randomly assigned to5groups:control group (C)、inhalation group (Ⅰ)、low dose group (2.5ml/kg, HSL)、medium dose group (5ml/kg, HSM)、 and high dose group (10ml/kg, HSH). The control group were received no treatment. The inhalation injury group were also received no treatment after injury. The hydrogen-rich saline group was administered i.p. hydrogen-rich saline (2.5ml/kg/5ml/kg/10ml/kg) after inhalation injury. All rats were sacrificed after24hours, and specimens were taken. The histopathological changes of lung tissue were observed under optical microscope and electrommicroscopy. Tumor necrosis factor a (TNF-a) in plasma was quantified, malondialdehyde (MDA) content and superoxidedismutase (SOD) activity of lung tissue were also detected, the NF-κBp65in lung speciments was investigate by immunohistochemistry technology, and the apoptosis of lung was monitor by terminal deoxynucleotidyl transfercase dUTP nik end labeling (TUNEL) assay.Result:1、Histopathological Examination by HE Staining:The alveolar structure was clear and complete, with no significant congestion and interstitial edema in group C. But in group I lung injury characterized by alveolar wall thickening, infiltration of neutrophils into the lung interstitium and alveolar space, consolidation, and alveolar hemorrhage was present. When compared with group I, there was a striking reduction of infiltrated inflammatory cells in group HSM and HSH, but there was no obvious changes in group HSL.2、Ultrastructural organization of lung tissues:With respect to ultrastructural histopathologic changes under electron microscopy in group I, Type I alveolar cell injury characterized by vacuoling, degranulation, Mitochondrial swelling, the perinuclear cisterna and the rough endoplasmic reticulum (the rough ER) Pool was dilated. Type Ⅱ alveolar epithelial cells was characterized by an active emptying of surface-active substances. Medium and high dose hydrogen-rich saline treatment resulted in a marked improvement in lung cell architecture when compared with those in the inhalation group. But the improvement was not obvious in the low dose treatment group3、TNF-α in serum:Serum TNF-α levels decreased both in group HSM and HSH compared with group Ⅰ (P<0.05). The decrease, however, was significant in group HSH than that in group HSM (P<0.05). The decrease was not obvious in group HSL (P<0.05).4、MDA and SOD in Lung Tissue:Lung MDA levels decreased both in group HSM and HSH compared to group Ⅰ, while SOD increased (P<0.05). The difference was more significant in group HSH than HSM (P<0.05), but was not obvious in group HSL (P<0.05)5、Effects of hydrogen-rich saline on NF-KBp65expression:There are few positive staining cells present in the lung tissue of group C, mainly located in the cytoplasm (NF-KBp65express little or no expression). Group Ⅰ is full of deeply stained NF-κB positive cells, both in cytoplasm and nuclear. While in HS groups, the positive cells were significantly reduced, especially in group HSM and HSH.The statistical results of mean optical density value for each group are consistent with the above statement. And the MOD values of group lower HSH are lower than that of group HSM (P<0.05)6、Effects of hydrogen-rich saline on Cell Apoptosis:Few cells of group C was stained Brown, while in group Ⅰ there were plenty positive cells stained Brown. Positive cells of group HSM, HSH were significantly reduced compared with Group I. The change was also not obvious in group HSL. The statistical results of apoptotic index (AI) for each group are consistent with the above statement. The difference between group HSM and HSH group was statistically significant(P<0.05).Conclusion:Hydrogen-rich saline treatment could significantly relieve acute lung injury induced by inhalation injury, and have dose-effect relationship.