Comparative effects of thermal and surgical trauma on rat muscle protein metabolism.
A modified intraperitoneal pool flooding technique, employing L-3H-tyrosine, was developed for measuring muscle protein synthetic rates following traumatic injury. Sufficient radiolabeled tyrosine was injected intraperitoneally to effect a six-fold increase in plasma tyrosine concentration (124-800 microM) resulting in constant, sustained specific radioactivities in plasma- and intracellular-free tyrosine pools. Localized vs systemic effects of thermal and surgical trauma on gastrocnemius muscle protein turnover were assessed 2 and 4 days postinjury. Thermal trauma increased total, myofibrillar, and sarcoplasmic muscle protein synthesis (44%) and protein degradation (300%). Conversely, surgical trauma decreased synthesis of total (24%), myofibrillar (14%), and sarcoplasmic (43%) muscle proteins without altering protein degradation. Short-term restriction of pair-fed controls did not affect either aspect of protein turnover.
Mermel
V L
VL
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Wolfe
B M
BM
Hansen
R J
RJ
Clifford
A J
AJ
D000818:Animals; D001835:Body Weight; D002056:Burns / Q000378:metabolism*; D004435:Eating; D005260:Female; D007044:Hysterectomy; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000293:injuries* / Q000378:metabolism; D009210:Myofibrils / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010529:Peritoneal Cavity; D051381:Rats; D011919:Rats, Inbred Strains; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D014443:Tyrosine / Q000097:blood / Q000378:metabolism
D009124:Muscle Proteins; D014443:Tyrosine; D009584:Nitrogen