Role of 15-F-2t-isoprostane in intestinal injury induced by intestinal ischemia/reperfusion in rats

摘要

15-F-2t-isoprostane is not only a specific marker of lipid peroxidation but also demonstrated to have potent bioactivities and can exert deleterious effects via activating thromboxane A2 receptor (TxA2r). We already demonstrated that lipid peroxidation represents a mechanism of intestinal ischemia/reperfusion (I/R) injury. But no studies have focused on 15-F-2t-isoprostane production and its biological actions on postischemic intestine during intestinal I/R. This study was carried to investigate whether the mechanism of endogenous 15-F-2t-isoprostane action is involved in the pathogenesis of intestinal I/R and administration of synthetic 15-F-2t-isoprostane could exacerbate intestinal insult after intestinal I/R in vivo and in vitro. In comparison with that of the sham control, we reported that endogenous 15-F-2t-isoprostane was liberated following intestinal I/R injury in rats, and using the TxA2r antagonist SQ29548 resulted in significant intestinal protection, evidenced by reduced lipid peroxidation, inflammation, and alleviated intestinal mucosal microvascular vasoconstriction. Further research found that in vivo administration of synthetic 15-F-2t-isoprostane exacerbated intestinal I/R injury by disturbing microvascular perfusion and accumulating anaerobic metabolism. Meanwhile, 15-F-2t-isoprostane did not change Hypoxia/Reoxygenation-induced IEC-6 cell viability but aggravated HUVECs cell death in vitro. Collectively, our results showed that locally produced 15-F-2t-isoprostane was in proportion to the severity of oxidative stress-induced intestinal injury and its detrimental effects can be attenuated through TxA2r inactivation. Exogenous 15-F-2t-isoprostane exacerbated intestinal I/R injury, which may be contributable to its biological actions on endothelium, rather than intestinal epithelium.