ABSTRACT
<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Ninety 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.</p><p><b>RESULTS</b>In 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).</p><p><b>CONCLUSION</b>Intestinal 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.</p>