Role of Lipid Peroxidation in Bacterial Translocation from the Small Intestine after Thermal Injury in Rats

Oxygen-derived free radicals have bran proved to play a role in the intestinalmucosa damage induced by ischemic reperfusion after burns,but their role in thebacterial translocation from the intestine to other organs is not documented so far.Theauthors intended to investigate this problem on 186rats,which were randomized into 5groups:the normal control group,the group receiving oral Pseudomonas,the group ofsimple burn injury,and the groups of combined oral Pseudomonas and burn injury withor without superoxide dismutase(SOD)treatment.The burn injury was 30% TBSA fullthickness scalding.The oral administered Pseudomonas was labdled with isothiocyanatefor tracing.The animals were killed in the 4th,12th,24th,48th,or 72nd hour afterinjury respectively.The changes of malondialdehyde(MDA)in the ilcal mucosa were ob-served with optical and electron microscope,and bacterial translocation from the intes-tine to the liver and blood stream was traced .The animals with combined injury and simple burns showed a marked increase ofileal mucosal MDA with the peak in the 12th hour accompanied with intense pathologicalchanges in the small intestine;the incidence of bacterial translocation from the intestineto other organs also increased.With SOD treatment,the MDA levd in the ileal mucosawas significantly lower,the pathological changes in the intestinal mucosa were allevia-ted,and the incidence of bacterial translocation from the intestine was lowered with nolabdled Pseudomonas isolated from the blood stream.In this study,it was demonstrated that free radicals are one of the factors ofintestinal mucosal damage and bacterial translocation from the intestine after burns,andSOD could protect the intestinal mucosal barrier from being injured and inhibit thebacterial translocation from the intestine.