CHANGES IN THE EXPRESSION OF RD-5 mRNA IN THE INTESTINE OF SCALDED RATS AFTER DELAYED FLUID RESUSCITATION / 解放军医学杂志

ABSTRACT

Objective To investigate whether intestinal bacterial translocation in scalded rat with delayed fluid resuscitation (DFR) was partly due to the reduction of the expression of rat defensin (RD), which was the most important defensin in rat intestinal defensin family excreted by Paneth cells. Methods Fifty-six SPF rats were randomized to 3 groups sham injury group (n=8); early resuscitation (ER) group (n=24), receiving fluid resuscitation immediately after scald (30% TBSA, third degree); delayed resuscitation group (n=24), receiving fluid resuscitation 6 hours after scald. The animals (n=6, at each time point) were sacrificed at 8, 24, 72 hours after injury. The expression of RD-5 in the terminal ileum was determined with PCR technic. Morphological changes in ileal Paneth cells were observed. Quantitative bacterial cultures of mesenteric lymph nodes (MLN), liver, spleen and lung were also done. Results In both ER group and DR group, ileal RD-5 mRNA expression level was significantly increased at 8 hours after injury, and it began to decrease at 24 hours until the end of the experiment, when the level was much lower than that of the sham group. When two experimental groups were compared, RD-5 mRNA expression level was significantly higher at 8 hours and significantly lower at 72 hours in DR group than in ER group. There were no obvious morphological changes in ileal Paneth cells in all 3 groups. Although high incidence of bacterial translocation was observed in both experimental groups, it was significantly higher in DR group than in ER group. Conclusions DFR did not cause Panth cell damage, and RD-5 changes did not contribute to bacterial translocation in 24 hours after DFR, as the increase in RD-5 mRNA might be an innate protective reaction. However, the decrease in RD-5 production at 72 hours may play a role in bacterial transloca- tion.