Objective: To study the rules of postburn expression of IGAM-1 and TNF-alpha and the rule of the change in the MPO activity in pulmonary tissue; to explore the influence of escharectomy on the changes in the above indices and to clarify the importance of escharectomy during shock stage.
Methods: One hundred and seventy six Wistar rats with 30% TBSA III degree back scald were used. RT-PCR was used in the examination of the expression of pulmonary tissue ICAM-1 and TNF-alpha mRNA and of the change in pulmonary MPO activity after escharectomy.
Results: The expressions of pulmonary ICAM-1 and TNF-alpha mRNA began to increase at 4 hour postburn and reached peak level at 12 and 24 hours postburn, respectively. Their expressions returned to near control level 96 hours postburn in rats undergone escharectomy during shock stage. On the contrary, they remained at a relative high level even on 7th postburn day in both non-operated rats and the rats receiving escharectomy 96 hours postburn. In addition, pulmonary tissue MPO activity fell to near control level in rats undergone escharectomy during shock stage, but it maintained a high level in rats in which escharectomy was not done during shock stage.
Conclusion: These findings suggest that eschar could induce the production of endothelial adhesion molecules. Therefore escharectomy as early as possible is very important to prevent the expression and release of adhesion molecules and the development of SIRS.