Route of feeding influences the production and expression of tumor necrosis factor alpha 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), tota l parenteral nutrition (TPN) (n = 22), and total enteral nutrition (TEN) (n = 11), continuously given a chow diet, TPN solution, or an enteral diet, r espectively, 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 w as significantly increased in the spleen, lungs, liver, and ileum of the ra ts receiving TPN compared with the CHOW and TEN rats. On the other hand, th e 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 d ay 7 after burn injury. These data suggest that TPN increases the expressio n 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.