【 Abstract 】 Objective To investigate the effects of 250 ml/m3 carbon monoxide (CO) inhalation or intraperitoneal infusion on lipopolysaccharide (LPS) induced rat intestinal tract injury, and to detect the roles of p38 mitogen-activated protein kinase (MAPK) pathway during CO administration. Methods After received 5 mg/kg LPS or an equal volume of normal saline by intravenous injection, 108 male SD rats were randomly divided into 6 groups: control group, CO inhalation (250 ml/m3) group, CO intraperitoneal infusion (250 ml/m3 at a rate of 2 L/min) group, LPS (5 mg/kg) group, LPS (5 mg/kg)+CO inhalation (250 ml/m3) group and LPS (5 mg/kg)+CO intraperitoneal infusion (250 ml/m3 at a rate of 2 L/min) group. The animals were differently sacrificed at 1, 3 and 6 h for the observation, and the ileum tissues were homogenized for determination the levels of platelet activator factor (PAF), intercellular adhesion molecule-1 (ICAM-1) and interlukin-10 (IL-10) with enzyme-lined immunosorbent assay, the content of maleic dialdehyde (MDA) with thiobarbitric acid, the activity of myeloperoxidase (MPO) with chemical method, the activity of superoxide dismutase (SOD) with hydroxylamine, the activity of phosphorylated p38 MAPK with Western blot, the pathology with light microscope, and the extents of cell apoptosis were showed by the ratio of the apoptotic cells which had less DNA to the total cells of a cell-suspension sample by using the flow cytometry after being stained with propidium iodide. Results Compared with both control, CO inhalation and intraperitoneal infusion group at the same time point, the levels of PAF, ICAM-1, MDA, MPO, cell apoptosis rate and the phosphorylated p38 MAPK protein in LPS group were increased, while IL-10 and SOD were decreased (P < 0.05 or 0.01), and accompanied by severe intestinal tract injury. There were no statistics differences at the different time point in the same group. PAF, ICAM-1, MDA, MPO and cell apoptosis rate in both LPS+CO inhalation group and LPS+CO intraperitoneal infusion group were lower, while IL-10 and SOD were higher than the corresponding value in LPS group at the same time point (all P < 0.05), with ameliorate injury too, but the expression of phosphorylated p38 MAPK was further up-regulated than that of LPS group (all P < 0.05). However, there were no significant differences in these parameters between LPS+CO inhalation group and LPS+CO intraperitoneal infusion group. Conclusion 250 ml/m3 CO inhalation and intraperitoneal infusion exerts the similar protection against LPS induced rat intestinal tract injury via anti-oxidant, anti-inflammation, and anti-apoptosis. This may involve the p38 MAPK pathway.
Citation: LIU Shaohua,MA Ke,XU Bing,XU Xinrong. Effects of Carbon Monoxide on Lipopolysaccharide Induced Rat Intestinal Tract Injury. CHINESE JOURNAL OF BASES AND CLINICS IN GENERAL SURGERY, 2008, 15(3): 174-179. doi: Copy