OBJECTIVETo investigate the changes in the expression of aquaporin 1 (AQP-1) in edematous small intestinal tissues of rats after severe burn and the effect of early enteral feeding on its expression.

METHODSNinety normal adult Wistar rats were randomly divided into normal control group (n=6), burn model group (n=42, with 30% TBSA III degrees) and early feeding group (n=42). Dry weight method, ELSIA and immunohistochemistry were used to observe and detect the water content and expression of AQP-1 in the intestinal tissue at 1, 4, 8, 12, 24, 48, and 72 h after the burns.

RESULTSIn the burn model group, the water content in the intestinal tissue increased at 4 h after the injury, reaching the peak level at 48 h; AQP-1 expression decreased at 8 h after severe burn and reached the lowest level at 48 h. AQP-1 expression level showed a significant inverse correlation to the water content (P<0.01). Compared with the burn model group, the rats in the early feeding group showed increased AQP-l expression and lessened edema in the small intestines, also demonstrating an inverse correlation between water content and AQP-l expression (P<0.01).

CONCLUSIONIntestinal AQP-1 expression gradually decreased and edema worsened in rats early after severe burn, reaching the lowest or the peak levels 48 h after the injury with an inverse correlation between them. Early enteral feeding can increase the expression of AQP-l in the small intestine to ameliorate the intestinal edema in rats with severe burn injury.