Objective: To explore the dynamic change in the expression of interleukin 18 (IL-18) mRNA in the tissue of scalded rats after delayed resuscitation.
Methods: Wistar rats inflicted by 30% TBSA III degree scalding were employed as the model. Fifty-four rats were randomly divided into normal control (C), scalding and delayed resuscitation group (SD) and preventive group of selective decontamination of digestive tract (SDD) group. The RT-PCR was applied to determine the tissue contents of IL-18 mRNA in intestine, lungs, liver and kidneys at 2, 8, 16 and 24 PBHs.
Results: Plasma level of LPS increased significantly and reached summit level at 8 and 24 PBHs after delayed resuscitation after scalding (P < 0.01), but decreased obviously (P < 0.05) after the preventive application of SDD. Furthermore, the expression of tissue IL-18 mRNA in lungs, liver and kidneys since 2 PBHs increased evidently when compared to that before scalding and reached peak value at 8 PBH (P < 0.01) and lasted up to 24 PBHs. The expression of IL-18 mRNA could be inhibited to varying degrees by preventive application of SDD (P < 0.05-0.01). It was indicated by correlative analysis that plasma level of LPS was positively correlated to the expression of tissue IL-18 mRNA in intestine, lungs and liver (r = 0.298, 0.290 and 0.365 respectively with P < 0.05-0.01).
Conclusion: The expression of tissue IL-18 mRNA in intestine, lungs, liver and kidneys increased significantly during early postburn stage and progressively enhanced thereafter. And the expression of tissue IL-18 mRNA in a variety of body tissue was significantly affected by post-traumatic endotoxemia.