OBJECTIVETo investigate the influence of escharectomy during shock stage on systemic and intestinal immune function and its mechanism in scalded rats.

METHODSNinety-six Wistar rats were employed in the study of which 8 were used as normal control group. The donor skin from the trunk in twenty-four rats were preserved in liquid nitrogen. The other 64 rats were subjected to 30% full-thickness scalding, and they were randomly divided into A (n = 24, no treatment after scalding), B (n = 24) and C (n = 16) groups. Physiological saline was intraperitoneally injected (50 ml/kg) on the 24 post-scalding hours to the rats in the B and C groups. The rats in B group underwent escharectomy during shock stage, and the excision wounds were covered with the cryo-preserved alloskin. The rats in C group received the same treatment as in B group but at 72 post-scalding hours. The change in the proliferative ability of splenic lymphocytes, the plasma and intestinal tissue content of interleukin 2 (IL-2), the contents of sIgA in intestinal mucus, and the content of DAO in the intestinal tissue were observed on 2, 4 and 8 post burn days (PBD) in A and B groups and also on 4 and 8 PBD in C group, respectively.

RESULTSThe splenocytic proliferative ability, IL-2 level in the plasma and intestinal tissue, and the sIgA content in intestinal mucus in the rats in A, B and C groups were lower than that in control group at all time points (P < 0.05). The proliferative ability of splenic lymphocytes in B group on 4 and 8 PBD and in C group on 8 PBD respectively was similar to that in control group. Whereas the IL-2 content in plasma and in intestinal tissue was higher in B and C groups than that in A group (P < 0.01). The sIgA content in intestinal mucus in B group was twice of that in C group respectively [(3.51 +/- 2.14) mg/g vs (1.40 +/- 0.64) mg/g, (3.03 +/- 0.95) mg/g vs (1.52 +/- 1.26) mg/g (P < 0.05 or P < 0.01)] on 4 and 8 PBD. The DAO activity in the intestinal tissue in A group was lower than that in control and B group (P < 0.05) on 4 and 8 PBD.

CONCLUSIONEscharectomy during shock stage might be beneficial to the recovery of the systemic and intestinal immune functions in rats with scalding injury.