Protein dynamics in skeletal muscle after trauma: local and systemic effects.

摘要: Injury is attended by accelerated skeletal muscle proteolysis. Accurate definition of this hypercatabolic response and its mediation requisite for specific therapy. We measured protein dynamics in the incubated intact epitrochlearis soleus muscles excised from both forelimbs hindlimbs rats 4 days after injury either a single hind limb scald (90 degrees C water 3 seconds; metabolic rate (MR) + 15%, urinary urea nitrogen (UUN) 10%) or 5% excision (dorsal skin removed to fascia; MR 40%, UUN 90%). Protein synthesis (3H phenylalanine incorporation) increased only injured scalded (+100%). Actin myosin breakdown (3-methylhistidine release) all tested was consistently larger than muscles. Breakdown mixed pool (tyrosine but less so 3-methylhistidine did not reach significance uninjured rats. With respect fiber type, white demonstrated more pronounced elevation measures at lower red muscle. Increasing associated with linear increase proteolysis no further change breakdown. conclude that distant injury; however, even when stress severe, unchanged. Muscles different composition are equally labile. Furthermore, myofibrillar labile pool.