Protein metabolism after injury with turpentine: a rat model for clinical trauma

Subcutaneous injections of turpentine induced discrete aseptic abscesses in rats without detectable injury to other tissues. Hypoalbuminemia and high circulating concentrations of alpha 2-macroglobulin were present after 48 h. Liver size, protein content, and protein fractional synthetic rate (FSR) were all increased, whereas loss of muscle protein occurred together with similar (45-50%) reductions in both intramuscular glutamine concentrations ([Gln]i, mmol/l intracellular water) and FSR. The rats became anorexic, but pair feeding (50% ad libitum for 48 h) produced a 22% increase in muscle [Gln]i and only an 18% reduction in muscle FSR. Dietary restriction therefore did not demonstrate the positive relationship between muscle [Gln]i and FSR, which has been observed in animal trauma studies. It is concluded that subcutaneous injections of turpentine produce many of the features of the acute-phase response to injury, and therefore this technique is recommended as a convenient laboratory model for studying various aspects of the protein metabolic response to injury.