Failure of infused beta-hydroxybutyrate to decrease proteolysis in man

Diabetes. 1983 Mar;32(3):197-205. doi: 10.2337/diab.32.3.197.

Abstract

Ketone bodies have been suggested to have a protein-sparing effect, since infusion of Na-beta-hydroxybutyrate in man decreases plasma alanine concentrations and urinary nitrogen (N) excretion. To test this hypothesis, six normal postabsorptive volunteers were infused with Na-beta-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 less than 0.05), whereas plasma leucine increased (P less than 0.05). Rates of alanine appearance increased (5.3 +/- 0.3 to 7.8 +/- 0.6 mumol/kg X 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-beta-hydroxybutyrate, four 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-beta-hydroxybutyrate, it is unlikely that hyperketonemia per se decreases proteolysis in postabsorptive man.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 3-Hydroxybutyric Acid
  • Adolescent
  • Adult
  • Alanine / blood
  • Animals
  • Bicarbonates / pharmacology
  • Blood Glucose / metabolism
  • Blood Proteins / metabolism*
  • Dogs
  • Female
  • Glucagon / blood
  • Humans
  • Hydrogen-Ion Concentration
  • Hydroxybutyrates / metabolism
  • Hydroxybutyrates / pharmacology*
  • Insulin / blood
  • Ketone Bodies / blood
  • Kinetics
  • Leucine / blood
  • Male
  • Sodium Bicarbonate

Substances

  • Bicarbonates
  • Blood Glucose
  • Blood Proteins
  • Hydroxybutyrates
  • Insulin
  • Ketone Bodies
  • Sodium Bicarbonate
  • Glucagon
  • Leucine
  • Alanine
  • 3-Hydroxybutyric Acid