ABSTRACT
Objective:To evaluate the effect of dexmedetomidine on intestinal injury in severely burned rats.Methods:One hundred and twenty healthy clean-grade male Sprague-Dawley rats, weighing 240-260 g, were divided into 4 groups ( n=30 each) using a random number table method: sham operation group (group Sham), sham plus dexmedetomidine group (group Sham+ Dex), severe burn group (group Burn), and severe burn plus dexmedetomidine group (group Burn+ Dex). Forty percent total body surface area of III degree burn model was developed in chloral hydrate-anesthetized rats.Dexmedetomidine was intravenously infused for 4 h at a rate of 5 μg·kg -1·h -1 starting from 3 h after establishing the model in Sham+ Dex group and Burn+ Dex group.The small intestinal tissues were removed for examination of the pathological changes which were scored and for determination of tumor necrosis factor-alpha (TNF-α) and high-mobility group box 1 protein (HMGB1) contents (by enzyme-linked immunosorbent assay), and expression of occludin and ZO-1 protein (by Western blot). The serum concentrations of 4-kD-FITC were measured at 90, 180, 360 and 720 min after establishing the model. Results:Compared with Sham group, the pathological scores of intestinal tissues, contents of TNF-α and HMGB1, serum concentrations of 4-kD-FITC at each time point were significantly increased, and the expression of occludin and ZO-1 was down-regulated in Burn group and Burn+ Dex group ( P<0.05), and no significant change was found in the parameters mentioned above in Sham+ Dex group ( P>0.05). Compared with Burn group, the pathological scores of intestinal tissues, contents of TNF-α and HMGB1, serum concentrations of 4-kD-FITC at each time point were significantly decreased, and the expression of occludin and ZO-1 was up-regulated in Burn+ Dex group ( P<0.05). Conclusion:Dexmedetomidine can reduce intestinal injury in severely burned rats, and the mechanism may be related to inhibiting inflammatory responses in the intestine.