Dexamethasone pretreatment alleviates intestinal ischemia-reperfusion injury.

BACKGROUND: Activated mast cells are involved in the pathogenesis of intestinal ischemia-reperfusion (I/R)-related injury. Dexamethasone has been widely used to protect organs from I/R injury. This study was conducted to investigate the impact of treatment with dexamethasone at different stages of the II/R process on mast cell infiltration and activity and intestinal injury. METHODS: Kunming mice were randomized and subjected to a sham surgery or the II/R induction by clamping the superior mesenteric artery for 30 min and then reperfusion. During the II/R induction, the mice were treated intravenously with dexamethasone (10 mg/kg) for 30 min before ischemia (pretreatment group), at 5 min after clamping the superior mesenteric artery (isc-treatment group), or at the beginning of perfusion (rep-treatment group), respectively. The levels of intestinal injury, mast cell infiltration and activity, tumor necrosis factor α (TNFα) and myeloperoxidase (MPO) activity in the intestines, and mouse survival rates were measured. RESULTS: The death rates, levels of intestinal injury, mast cell infiltration and activity, and tumor necrosis factor α and myeloperoxidase activity in the intestinal tissues from the II/R group were similar to those from the isc-treatment and rep-treatment groups of mice and were significantly higher than those from the sham group. In contrast, pretreatment with dexamethasone significantly mitigated the II/R-induced mast cell infiltration and activity, inflammation, and intestinal injury and reduced the death rates in mice. CONCLUSIONS: Pretreatment with dexamethasone inhibits II/R injury by reducing mast cell-related inflammation in mice.