Effects of p38 mitogen-activated protein kinase in protection of carbon monoxide against lipopolysaccharide induced rat small intestine injury / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To investigate the effects of low concentration carbon monoxide (CO) inhalation or intraperitoneal infusion on lipopolysaccharide (LPS) induced rat small intestine injury and to detect the roles of p38 mitogen-activated protein kinase (MAPK) pathway during CO administration.</p><p><b>METHODS</b>SD rats with small intestine injury induced by 5 mg/kg LPS intravenous injection were challenged by room air, 2.5 x 10(-4)(V/V) CO inhalation or intraperitoneal infusion for 1 h, 3 h and 6 h differently. Then all animals were sacrificed, and the ileum tissues were homogenized for determination the levels of platelet activator factor(PAF) and intercellular adhesion molecule-1 (ICAM-1) with enzyme-lined immunosorbent assay, the pathology with light microscope, and the phosphorylated p38 MAPK expression with Western blot.</p><p><b>RESULTS</b>Compared with either control, CO inhalation or intraperitoneal infusion group at the same time point, the levels of PAF, ICAM-1 and the phosphorylated p38 MAPK of LPS group were increased (all P < 0.01), but there were no statistics differences at the different time point of this group. PAF and ICAM-1 in both LPS injection + CO inhalation group and LPS injection + CO intraperitoneal infusion group were significantly lower than the corresponding value in LPS injection group at the same time point (all P < 0.05), while the expression of phosphorylated p38 MAPK was further up-regulated than that of LPS injection group (P < 0.05). However, there were no significant differences in these parameters between LPS injection+ CO inhalation group and LPS injection+ CO intraperitoneal infusion group.</p><p><b>CONCLUSION</b>Low concentration CO inhalation and intraperitoneal infusion exerts the similar protection against LPS induced rat small intestine injury via down-regulating PAF and ICAM-1 expression. This may involve the p38 MAPK pathway.</p>