Albumin and fibrinogen syntheses increase while muscle protein synthesis decreases in head-injured patients.
The effect of trauma on protein metabolism was investigated in the whole body, muscle, and liver in severely head-injured patients presenting an acute inflammatory response by comparison to fed control subjects receiving a similar diet. Nonoxidative leucine disposal (an index of whole body protein synthesis) and muscle, albumin, and fibrinogen synthesis were determined by means of a primed, continuous infusion of L-[1-13C]leucine. Nonoxidative leucine disposal increased by 28% in the patients (P < 0.02). Fractional muscle protein synthesis rate decreased by 50% (P < 0.01) after injury. Fractional and absolute fibrinogen synthesis rates were multiplied by two and nine, respectively, after injury (P < 0.001). Albumin levels were lower in patients (25.2 +/- 1.2 g/l, means +/- SE) than in controls (33.7 +/- 1.2 g/l, P < 0.001). However, fractional albumin synthesis rates were increased by 60% in patients (11.4 +/- 1.0%/day) compared with controls (7.3 +/- 0.4%/day, P < 0.01). Therefore, 1) head trauma induces opposite and large changes of protein synthesis in muscle and acute-phase hepatic proteins, probably mediated by cytokines, glucocorticoids, and other stress hormones, and 2) in these patients, hypoalbuminemia is not due to a depressed albumin synthesis.
Mansoor
O
O
Département de Réanimation, Centre Hospitalier Universitaire, Clermont Ferrand, France.
Cayol
M
M
Gachon
P
P
Boirie
Y
Y
Schoeffler
P
P
Obled
C
C
Beaufrère
B
B
D001798:Blood Proteins / Q000378:metabolism; D002151:Calorimetry; D006259:Craniocerebral Trauma / Q000378:metabolism*; D004734:Energy Metabolism; D005340:Fibrinogen / Q000096:biosynthesis*; D006801:Humans; D007930:Leucine / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012016:Reference Values; D012709:Serum Albumin / Q000096:biosynthesis*
D001798:Blood Proteins; D011506:Proteins; D012709:Serum Albumin; D005340:Fibrinogen; D007930:Leucine