Route of feeding influences the production and expression of tumor necrosis factor α in burned rats

The effect of nutritional route on tumor necrosis factor alpha. (TNF-alpha) production in burned rats was examined. Scald burns covering about 30% of the whole body surface area were inflicted on 43 male Wistar rats weighing about 200g. The animals were divided into three groups: CHOW (n = 10), total parenteral nutrition (TPN) (n = 22), and total enteral nutrition (TEN) (n = 11), continuously given a chow diet, TPN solution, or an enteral diet, respectively, for 7 days after the burn injury. The rate of detection of TNF-alpha in plasma on day 7 was significantly higher in the TPN group than in the CHOW or TEN groups. The messenger RNA (mRNA) expression of TNF-alpha was significantly increased in the spleen, lungs, liver, and ileum of the rats receiving TPN compared with the CHOW and TEN rats. On the other hand, the expression of TNF-alpha mRNA was markedly decreased in the thymus of the TPN group compared with the CHOW group. The mortality rate in the TPN group (63.6%) was higher than that in the CHOW (0.0%) or TEN (27.3%) groups on day 7 after burn injury. These data suggest that TPN increases the expression of TNF-alpha mRNA in organ tissues and systemic TNF-alpha production, and reduces the survival rate of rats after thermal injury, but TEN does not.