TY - JOUR
T1 - Failure of infused β-hydroxybutyrate to decrease proteolysis in man
AU - Miles, J. M.
AU - Nissen, S. L.
AU - Rizza, R. A.
AU - Gerich, J. E.
AU - Haymond, M. W.
PY - 1983
Y1 - 1983
N2 - Ketone bodies have been suggested to have a protein-sparing effect, since infusion of Na-β-hydroxybutyrate in man decreases plasma alanine concentrations and urinary nitrogen (N) excretion. To test this hypothesis, 6 normal postabsorptive volunteers were infused with Na-β-hydroxybutyrate for 3 h. Rates of glucose, leucine carbon, and alanine appearance and disappearance from the plasma space were traced with [3-3H]glucose, L-[6,6,6-2H3]leucine, and [2,3,3,3-2H4]alanine. Rates of leucine N appearance and disappearance and the rate of transfer of leucine N to alanine were assessed with [15N]leucine. During ketone body infusion, plasma alanine decreased (P < 0.05), whereas plasma leucine increased (P < 0.05). Rates of alanine appearance increased (5.3 ± 0.3 to 7.8 ± 0.6 μmol/kg . min), but the increase in its rate of disappearance was slightly greater, accounting for the decrease in plasma alanine concentration. Leucine N flux and the rate and percent of leucine N transferred to alanine increased, whereas leucine carbon flux was unchanged. To determine the effect of the alkalemia induced by Na-β-hydroxybutyrate, 4 additional subjects were infused with NaHCO3. Alkalemia had no effect on leucine N or carbon flux or on the rate of appearance of alanine, but increased the rate of alanine disappearance, resulting in a decrease in the plasma alanine concentration. Since the rate of appearance of leucine carbon was unaltered during the infusion of Na-β-hydroxybutyrate, it is unlikely that hyperketonemia per se decreases proteolysis in postabsorptive man.
AB - Ketone bodies have been suggested to have a protein-sparing effect, since infusion of Na-β-hydroxybutyrate in man decreases plasma alanine concentrations and urinary nitrogen (N) excretion. To test this hypothesis, 6 normal postabsorptive volunteers were infused with Na-β-hydroxybutyrate for 3 h. Rates of glucose, leucine carbon, and alanine appearance and disappearance from the plasma space were traced with [3-3H]glucose, L-[6,6,6-2H3]leucine, and [2,3,3,3-2H4]alanine. Rates of leucine N appearance and disappearance and the rate of transfer of leucine N to alanine were assessed with [15N]leucine. During ketone body infusion, plasma alanine decreased (P < 0.05), whereas plasma leucine increased (P < 0.05). Rates of alanine appearance increased (5.3 ± 0.3 to 7.8 ± 0.6 μmol/kg . min), but the increase in its rate of disappearance was slightly greater, accounting for the decrease in plasma alanine concentration. Leucine N flux and the rate and percent of leucine N transferred to alanine increased, whereas leucine carbon flux was unchanged. To determine the effect of the alkalemia induced by Na-β-hydroxybutyrate, 4 additional subjects were infused with NaHCO3. Alkalemia had no effect on leucine N or carbon flux or on the rate of appearance of alanine, but increased the rate of alanine disappearance, resulting in a decrease in the plasma alanine concentration. Since the rate of appearance of leucine carbon was unaltered during the infusion of Na-β-hydroxybutyrate, it is unlikely that hyperketonemia per se decreases proteolysis in postabsorptive man.
UR - http://www.scopus.com/inward/record.url?scp=0020659662&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0020659662&partnerID=8YFLogxK
U2 - 10.2337/diab.32.3.197
DO - 10.2337/diab.32.3.197
M3 - Article
C2 - 6298041
AN - SCOPUS:0020659662
SN - 1931-857X
VL - 32
SP - 197
EP - 205
JO - Unknown Journal
JF - Unknown Journal
IS - 3
ER -