Epinephrine's ketogenic effect in humans is mediated principally by lipolysis
Avogaro, A.; Cryer, P.E.; Bier, D.M.
American Journal of Physiology 263(2 Pt 1): E250-E260
1992
ISSN/ISBN: 0002-9513 PMID: 1514604 Document Number: 398810
The effects of epinephrine on the kinetic parameters of circulating acetoacetate (AcAc) and beta -hydroxybutyrate ( beta -OBH) were studied and the relative roles of enhanced free fatty acid (FFA) delivery to the liver and altered intrahepatic conversion of FFA to ketone bodies as a function of plasma epinephrine concentration were assessed. The indirect effects of insulin and glucagon on these processes were also examined. 13 healthy subjects were studied on 2 occasions duing an infusion of epinephrine, i.e. when plasma insulin and glucagon values were free to change and again when circulating concentrations of these hormones were held constant. The data were compared with similar kinetic parameters determined in an additional group of control subjects where FFA values were increased by an infusion of Intralipid plus heparin to match values found in the subjects who had received epinephrine infusions. It is concluded that epinephrine's ketogenic effect in humans is primarily the result of its effect on lipolysis. It is accompanied by a significant increased rate of ketone body interconversion, is manifest largely as an increase in plasma beta -OBH appearance at high plasma epinephrine values, and is not limited by portal insulin at postabsorptive levels.