AIM:To investigate the effect of L-arginine(L-Arg) on expression of bcl-2,bax mRNA during pulmonary ischemia and reperfusion injury(PIRI) in rabbits.METHODS: Single lung ischemia and reperfusion animal model was used in vivo.The rabbits were randomly divided into three groups: sham operated group(sham,n=12),ischemia-reperfusion group(I/R,n=12) and I/R+ L-arginine group(L-Arg,n=12).Changes of several parameters,which included apoptotic index(AI),wet to dry ratio of lung tissue weight(W/D) and index of quantitative assessment of histologic lung injury(IQA),were measured at 300 min after reperfusion in lung tissue.Meanwhile the location and expression of bcl-2,bax mRNA as well as the ratio of bcl-2 mRNA/bax mRNA were observed.The lung tissue was prepared for light microscopic and electron microscopic observation at 60,180 and 300 min after reperfusion.RESULTS: As compared with I/R group,in intima and extima of small pulmonary artery,alveoli,and bronchiole epithelia,the expression of bcl-2 mRNA and the ratio of bcl-2 mRNA/bax mRNA were increased,and the expression of bax mRNA was decreased in L-Arg treatment group.The values of AI,W/D and IQA showed significantly lower than that in I/R group at 180 minutes after reperfusion in lung tissue(P

Objective:To explore the mechanism by which Pien Tze Huang improves liver Kupffer cell damage induced by lipopolysaccharide (LPS) by regulating the expression of miR-155.Methods:LPS induced liver Kupffer cells to establish a cell injury model to simulate septic liver injury. RT-qPCR was used to detect the expression of miR-155 in damaged cells, and RT-qPCR, Western Blot, ELISA and flow cytometry were used to evaluate the inflammatory response and apoptosis of damaged cells. Then we treated LPS-induced Kupffer cells with Pien Tze Huang at different concentrations (0 mg/L, 5 mg/L, 10 mg/L and 15 mg/L), and detected the expression of miR-155 in the cells, the inflammatory response of the cells and Apoptosis rate. MiR-155 was silenced in the cell injury model, and RT-qPCR, Western Blot, ELISA and flow cytometry were used to evaluate the effect of miR-155 on inflammatory response and apoptosis of model cells. Overexpression of miR-155 in damaged cells treated with Pien Tze Huang was used to detect changes in cellular inflammatory response and apoptosis. Data are expressed in the form of mean ± standard deviation, and each group of data is analyzed using t test or one-way analysis of variance.Results:In the LPS-induced liver Kupffer cell injury model, the expression of miR-155 was significantly increased ( P<0.05), the expression levels of pro-inflammatory factors IL-6 and TNF-α were significantly increased, and the anti-inflammatory factor IL-10 was significantly increased. was inhibited ( P<0.05), and the cell apoptosis rate was significantly increased ( P<0.05). After Pien Tze Huang treatment, the expression of miR-155 in damaged liver cells was inhibited ( P<0.05), the levels of cellular inflammatory factors IL-6 and TNF-α were inhibited, and the expression of anti-inflammatory factor IL-10 was promoted ( P<0.05). Inhibit cell apoptosis ( P<0.05). Silencing miR-155 reduced the inflammatory response and apoptosis rate of cells ( P<0.05). Overexpression of miR-155 can reverse the effect of Pien Tze Huang on liver cell injury ( P<0.05). Conclusions:In the model of LPS-induced liver Kupffer cell injury, Pien Tze Huang can inhibite the inflammatory response and apoptosis of cells by inhibiting the expression of miR-155.