Study of the expression of TNF-α,oxygen free radical and the effects of early enteral nutrition intervention in rats with sereve burn injury

Objective To investigate the effect of enteral feeding at early stage on the expression of TNF-α and oxygen free radical(OFR) and the protective effects on the organism,so as to provide the experimental basis of clinical therapy of enteral feeding in patients with severe burns.Methods The severe burn model was established with Wistar rats.Burned Wistar rats were randomly devided into fasting group(n=10) and early enteral nutrition group(n=10) to compare with the control group(n=10).The rats in the fasting group and early nutrition group were given intraperitoneal injection of balance liquid and gastric clysis of nourishment product respectively,30 ml every 6 h within 48 h after burn injury.Subsequently,the rats were allowed access to food ad libitum until 7 th day and the mortalities of the three groups were calculated.The expression of blood TNF-α and OFR of the three groups at 6,12,24,48,72 h and on 7d were detected.The fibroblasts in the wound were observed under the electron microscope and the denaturalization of hepatocytes was observed by H-E staining under the light microscope.Results The mortality of fasting group,early nutrition group and control group was 80%,30% and 0,respectively.Compared with the control group,the level of TNF-α and malonaldehyde(MDA) obviously ascended,while the level of super oxide dismutase(SOD) obviously descended in the fasting group(P0.05).Compared with the fasting group,the level of TNF-α and MDA descended,while SOD level obviously ascended in early nutrition group(P0.05).The ultrastructure of fibroblast cells in the wound of early enteral nutrition group was less severely damaged than in the fasting group,accompanied by visible apoptotic fibroblasts.The degree of hepatic steatosis in the early enteral nutrition group was lower than in the fasting group.Conclusion Early enteral nourishment could reduce the expression of TNF-α and OFR on the whole,and help heal the local wounds relieve injuries to the viscera.