A RABBIT MODEL FOR METABOLIC STUDIES AFTER BURN INJURY

Background. A rabbit burn model was developed and characterized, which will allow conduct of repeated, noninvasive and more sophisticated in vivo metabolic studies to explore the pathophysiology of burn injury, owing to its larger blood volume and tissue mass than the rat. Materi als and methods. A 20% body surface, full thickness burn was applied t o the backs of six anesthetized rabbits by immersion into a boiling-wa ter bath for 10 a, followed by resuscitation with saline. Resting ener gy expenditure (REE) was measured daily in pre- and postburn periods, Whole body protein kinetics were evaluated using L-[1-C-13]leucine tra cer, on the preburn and the third postburn day. Fasting plasma glucose was also measured. Results. A significant elevation of REE began on t he second postburn day and reached 34 +/- 8% above the preburn level ( P < 0.05, paired t test) on the third postburn day. The fasting plasma leucine flux and oxidation were significantly elevated from their pre burn levels (both P < 0.05), indicating an accelerated proteolysis and a more negative body protein balance (P < 0.05); however, the rate of whole body protein synthesis did not differ significantly pre- and po stburn injury. Fasting plasma glucose also increased (P < 0.001) on th e third postburn day. The burn scar remained intact during the study, without any sign of infection. Conclusions. The metabolic changes obse rved in this animal model can be attributed to burn injury per se and they mimic those for flow phase in burn patients. This rabbit burn mod el should be suitable for exploring mechanistic aspects of the burn-in duced changes in metabolism and nutrient balance. (C) 1998 Academic Pr ess.