Journal - Zhongguo wei zhong bing ji jiu yi xue = Chinese critical care medicine = Zhongguo weizhongbing jijiuyixue (China )

Abstract :

OBJECTIVE: To study the expressions of mRNA and protein of ubiquitin in diaphragmatic muscle in burned rats with sepsis. METHODS: The model of burn sepsis was replicated by subjecting the rats to 30 percent total body surface area (TBSA) III degree burn followed immediately by administration of endotoxin (6 mg/kg) into the peritoneal cavity. The rats were randomly divided into 2-and 6-hour groups and a normal control group, with 9 rats in each group. The expressions of ubiquitin mRNA in the diaphragmatic muscle was determined with Northern blot analysis. The expressions of ubiquitin protein in the diaphragmatic muscle were assayed with immunohistochemical method. RESULTS: The expressions of the ubiquitin mRNA (2.4 kb and 1.2 kb) in diaphragmatic muscle of burn rats with sepsis were significantly higher than that of normal control group, especially the 2.4 kb stripe (all P<0.01). A notable increase in the expressions of the ubiquitin mRNA was found in the 6-hour group compared with the 2-hour group (all P<0.01). The expressions of the ubiquitin protein in diaphragmatic muscle of burn rats with sepsis were significantly increased after injury compared with the normal control group. CONCLUSION: The expressions of mRNA and protein of ubiquitin in diaphragmatic muscle are continuously increased soon after injury, suggesting that the protein degradation rate is increased in burn with sepsis. The finding is helpful in the study of the change in metabolism of diaphragmatic muscle and respiratory function.