Effect of dexmedetomidine on acute liver injury in rats with endotoxemia

Objective To evaluate the effect of dexmedetomidine on acute liver injury in rats with endotoxemia. Methods Eighteen adult male Sprague-Dawley rats, aged 3-4 months, weighing 250-300 g, were randomly divided into 3 groups (n=6 each) using a random number table: control group (group C), endotoxin group (group E), and dexmedetomidine group (group D). In E and D groups, lipopolysaccharide 5 mg/kg was injected via the femoral vein of rats anesthetized with chloral hydrate. In group D, dexmedetomidine was infused with a 7 μg/kg loading bolus over 15 min after injection of lipopolysaccharide, followed by a 6 h continuous infusion of 5 μg·kg-1·h -1. The equal volume of normal saline was given instead in E and C groups. After the end of administration, blood samples from the femoral vein were drawn for determination of tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) concentrations in serum (by using enzyme-linked immunosorbent assay), and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in serum (using the International Federation of Clinical Chemistry and Laboratory Medicine reference procedures). Liver specimens were obtained for examination of pathologic changes with electron microscope. Results Compared with group C, the serum ALT and AST activities and TNF-α and IL-1β concentrations were significantly increased in E and D groups. Compared with group E, the serum ALT and AST activities and TNF-α and IL-1β concentrations were significantly decreased in group D. The pathologic changes of livers were obvious in group E, and were significantly reduced in group D compared with group E. Conclusion Dexmedetomidine can alleviate acute liver injury in rats with endotoxemia, and the underlying mechanism is associated with inhibition of systemic inflammatory responses. Key words: Dexmedetomidine; Endotoxemia; Liver