STUDY ON THE CHANGES IN UBIQUITIN AND UBIQUITINATED PROTEIN IN RAT SKELETAL MUSCLE DURING POSTBURN PERIOD / 解放军医学杂志

ABSTRACT

To study the regularity of ubiquitin and ubiquitinated protein expression in rat skeletal muscle after burn injury, the molecular mechanism of skeletal muscle protein catabolism was investigated. Wistar rats were inflicted on a 30% full thickness burn. They were grouped according to the time of sacrifice2, 6, 12 and 24 hours after burn, each group included normal control. The extensor digitorium logus (EDL) muscle was taken to assay the proteolytic rate and the expression of ubiquitin and ubiquitinated protein during postburn period. It was found that proteolytic rate of EDL muscle was markedly enhanced, especially in myofibrillar proteolytic rate, by 185% and 153% at 12h and 24h after burn injury, respectively. The contents of free ubiquitin and ubiquitinated protein in rat EDL muscle were significantly increased after burn injury, especially at 12 and 24 hour. The contents of free ubiquitin and ubiquitinated protein increased 33% and 186% at 12h postburn, increased 30% and 163% at 24h,respectively. The high protein catabolism of skeletal muscle during postburn stage is in close relation to high expression of free ubiquitin and ubiquitinated protein.