title: Leucine incorporation into skeletal muscle proteins in vitro and protein synthesis by isolated ribosomes from skeletal muscle around a high velocity missile injury.
abstract: Protein synthesis in skeletal muscle around a high velocity missile injury was investigated in two series of experiments. In the first series a shot wound was induced in the hindleg of dogs. Muscle biopsies were taken at various distances from the wound channel and bundles of muscle fibre were incubated in a medium containing 14C-leucine under protein synthetizing conditions. A significant reduction in the rate of leucine incorporation into muscle protein was seen in the adjacent to the wound channel. At a distance of 3 cm from the bullet track no reduction in leucine incorporation into protein occurred. In the second series of experiments a high velocity missile injury was induced in the hindleg of pigs. The capacity of ribosomes to incorporate 14C-phenylalanine into protein was analyzed. Ribosomes were isolated from skeletal muscle around the shot wound. The effect of missile injury alone and that of the combined effect of missile injury and hemorrhage were studied. A marked reduction in ribosomal activity was found in tissue adjacent to and up to 2.4 cm from the wound channel. At a distance of 3 cm from the wound ribosomal activity remained unaffected. Ribosomal activity was significantly more reduced in tissue close to the wound channel after missile injury and hemorrhage than after missile injury alone. The reduced capacity for protein synthesis in muscle around the missile injury found in this study probably reflects a lowered cellular energy level. The local metabolic changes were aggrevated in animals where hemorrhage was also induced indicating that in the clinical situation prevention of hemorrhage and hypovolemia might reduce the amount of tissue that has to be excised following a short wound.
mesh_terms: D000818:Animals; D004285:Dogs; D006614:Hindlimb / Q000293:injuries*; D066298:In Vitro Techniques; D007930:Leucine / Q000378:metabolism*; D009124:Muscle Proteins / Q000096:biosynthesis*; D009132:Muscles / Q000378:metabolism* / Q000648:ultrastructure; D010649:Phenylalanine / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013552:Swine; D014948:Wounds, Gunshot / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D010649:Phenylalanine; D007930:Leucine