TY - JOUR
T1 - The effect of hemodialysis on protein metabolism
T2 - A leucine kinetic study
AU - Lim, Victoria S.
AU - Bier, Dennis M.
AU - Flanigan, Michael J.
AU - Sum-Ping, Sam T.
PY - 1993/6
Y1 - 1993/6
N2 - To assess the effect of hemodialysis on protein metabolism, leucine flux was measured in seven patients before, during, and after high efficiency hemodialysis using cuprophane dialyzers and bicarbonate dialysate during a primed-constant infusion of L-[1-13C]leucine. The kinetics [μmol/kg per h, mean±SD] are as follows: leucine appearance into the plasma leucine pool was 86±28, 80±28, and 85±25, respectively, before, during, and after dialysis. Leucine appearance into the whole body leucine pool, derived from plasma [1-13C]α-ketoisocaproate enrichment, was 118+31, 118±31, and 114±28 before, during, and after dialysis, respectively. In the absence of leucine intake, appearance rate reflects protein degradation, which was clearly unaffected by dialysis. Leucine oxidation rate was 17.3±7.8 before, decreased to 13.8+7.8 during, and increased to 18.9±10.3 after dialysis (P = 0.027). Leucine protein incorporation was 101 ±26 before, was reduced to 89±23 during, and returned to 95±23 after dialysis (P = 0.13). Leucine net balance, the difference between leucine protein incorporation and leucine release from endogenous degradation, was -17.3±7.8 before, decreased to -28.5±11.0 during, and returned to -18.9±10.3 after dialysis (P < 0.0001). This markedly more negative leucine balance during dialysis was accountable by dialysate leucine loss, which was 14.4±6.2 μmol/kg per h. These data suggest that hemodialysis using a cuprophane membrane did not acutely induce protein degradation. It was, nevertheless, a net catabolic event because protein synthesis was reduced and amino acid was lost into the dialysate.
AB - To assess the effect of hemodialysis on protein metabolism, leucine flux was measured in seven patients before, during, and after high efficiency hemodialysis using cuprophane dialyzers and bicarbonate dialysate during a primed-constant infusion of L-[1-13C]leucine. The kinetics [μmol/kg per h, mean±SD] are as follows: leucine appearance into the plasma leucine pool was 86±28, 80±28, and 85±25, respectively, before, during, and after dialysis. Leucine appearance into the whole body leucine pool, derived from plasma [1-13C]α-ketoisocaproate enrichment, was 118+31, 118±31, and 114±28 before, during, and after dialysis, respectively. In the absence of leucine intake, appearance rate reflects protein degradation, which was clearly unaffected by dialysis. Leucine oxidation rate was 17.3±7.8 before, decreased to 13.8+7.8 during, and increased to 18.9±10.3 after dialysis (P = 0.027). Leucine protein incorporation was 101 ±26 before, was reduced to 89±23 during, and returned to 95±23 after dialysis (P = 0.13). Leucine net balance, the difference between leucine protein incorporation and leucine release from endogenous degradation, was -17.3±7.8 before, decreased to -28.5±11.0 during, and returned to -18.9±10.3 after dialysis (P < 0.0001). This markedly more negative leucine balance during dialysis was accountable by dialysate leucine loss, which was 14.4±6.2 μmol/kg per h. These data suggest that hemodialysis using a cuprophane membrane did not acutely induce protein degradation. It was, nevertheless, a net catabolic event because protein synthesis was reduced and amino acid was lost into the dialysate.
KW - Hemodialysis
KW - Leucine kinetics
KW - Protein flux
UR - http://www.scopus.com/inward/record.url?scp=0027289732&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027289732&partnerID=8YFLogxK
U2 - 10.1172/JCI116477
DO - 10.1172/JCI116477
M3 - Article
C2 - 8514855
AN - SCOPUS:0027289732
SN - 0021-9738
VL - 91
SP - 2429
EP - 2436
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 6
ER -