Abstract:

Objective The aim of this study was to evaluate the effect and mechanism of lactulose on acute lung injury in rats with hemorrhagic shock. Methods SD rats without lactulose pretreatment were divided into three groups：sham operation group（10 rats），normal saline resuscitation group（10 rats），and lactulose treatment group（1 rats）（10 animals）ahead of 60 min before preparation of hemorrhagic shock. After the successful catheterization of the four groups of experimental animals，the hemorrhagic shock model was prepared and the vital signs were continuously monitored. The blood gas and lactic acid values were measured at 0 min，30 min and 270 min. The HMGB1 in lung tissue was detected by western method and the IL⁃6 as well as IL⁃1 in blood were detect⁃ ed by ELISA method β. SOD and MDA in lung tissue were detected by colorimetry at 270 min. The expression of MPO in lung tissue was detected by TBA at 270 min. The pathological sections of lung tissue were analyzed under light microscope. Results At 270min，the pO2 value of the control group was significantly lower than that of the blank group，experimental group 1 and experimental group 2（P < 0.05）. IL⁃6，IL⁃1 β，SOD，MDA and MPO in blank group were statistically significant different with control group，experimental group 1 and experimental group 2 respectively（P < 0.05）. The comparison between control group and experimental group 2 was also statistically significant different（P < 0.05）. Compared with experimental group 2，experimental group was also statistically significant different（P < 0.05）. HMGB1 in control group was statistically significant different with blank group， experimental group 1 and experimental group 2 respectively（P < 0.05）. The results of lung pathological sections showed that the alveolar endothelium and alveolar tissue in experimental group 1 were significantly damaged and inflammatory cell infiltration was significant obviously when comparing with experimental group 2. The destruction of alveolar endothelium and alveolar tissue and inflammatory cell infiltration in the control group were more obvious than those in experimental group 1 and experimental group 2. Conclusion Lactulose could promote the production of SOD and inhibit the production of HMGB1，and thus inhibit the release of IL⁃6，IL⁃1 β，MDA，MPO and other inflammatory mediators for protecting the lung tissue.

Key words:

lactulose, hemorrhagic shock, injury of lungs, SD rats