| Objective:To observe the effects of glutamine (Gln) enriched enteral nutrition on multiple organs glutamine metabolism and liver function in burned rats and explore its possible mechanism.Methods:Adult Sprague Dawley rats (weighing200g to260g) were randomly divided into normal control (C) group, burn control (B) group, and burn+Gln (B+Gln) group. Group C received anesthesia and shaving, but not burn; group B and B+Gln were treated with94℃water soak for18seconds, caused30%total body surface area of full thickness burn. To estimate rat nutrition calories by determinating the resting energy expenditure(REE).After burn injury, animals would be received the same standard enteral nutrition protocol.Groups intaked of nutraceutical which was isocaloric by mouth freely (2times a day),single cage feeding; group B+Gln were given the nutraceutical that was added Gln(2.0g/kg.d),2times a day, add the same amount of compound amino acid in group C and B.1.The contents of Gln in serum, liver, muscle, intestinal mucosa post burn7d,14d were measured by spectrophotometry;2.The glutamine synthetase(GS) activity in liver,muscle post burn7d,14d were measured by spectrophotometry;3.The glutaminase (GA) activity in liver,intestinal mucosa post burn7d,14d were measured by spectrophotometry;4. The concentration of alanine aminotransferase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) in serum post burn7d,14d were measured by automatic biochemical analyzer.Results:Each group of rats eating effect better, could intake of food according to the plan.1.Compared with group C, the contents of Gln in serum,liver,muscle,intestinal mucosa in group B decreased remarkably post burn7d,14d (P<0.05or P<0.01) compared with group B, the contents of Gln in serum,liver,muscle,intestinal mucosa in group B+Gln increased notably (P<0.05or P<0.01) in varying degrees;2. Compared with group C, the liver GS activity in group B did not change significantly,however the muscle GS activity in group B increased remarkably post burn7d,14d (P<0.01); compared with group B, both the liver and muscle GS activity in group B+Gln were higher (P<0.05);3.Compared with group C, both the liver and intestinal mucosa GA activity in group B decreased in varying degrees; compared with group B,both the liver and intestinal mucosa GA activity in group B+Gln increased with statistical significance (P<0.05);4. Compared with group C, the concentration of ALT, AST, ALP in group B and B+Gln increased in varying degrees post burn7d,14d, statistically significant(P<0.01); compared with group B, these indicators decreased in group B+Gln.Conclusion:1.The Gln content is decreased after severe burns in serum, liver, skeletal muscle and intestine, enteral supplementation enriched with Gln can increase the Gln content in blood and tissues obviously, alleviate the Gln exhaustion.2.The demand of Gln is increased after severe burns, improving the GS activity in muscle. Enteral supplementation enriched with Gln can improve the GS activity in muscle and liver further more, the synthesis and output of Gln is increased, supplying for tissue cell to metabolise and utilize at the same time, but also reducing the muscle protein breakdown.3.The activity of GA in liver and intestinal mucosa is decreased after severe burns. Enteral supplementation enriched with Gln can improve the activity of GA, promot liver and intestine to decompose Gln and supply energy for cells, like intestinal epithelial cells and immune cells.These can maintain the intestinal mucosal barrier.4. After severe burns, glutamine-supplemented enteral feeding can improve the activity of the key enzyme in Gln metabolism, promote the synthesis and decomposition of Gln, improve the Gln metabolism and exert its biological efficacy.5.Severe burns lead to liver damage and increase the release of enzymes that are related to the liver cells in serum, enteral supplementation enriched with Gln can reduce the injury of liver cells and maintain the liver function. |
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