Journal of Lipid Research, Vol 25, 160-174, Copyright © 1984 by Lipid Research, Inc.
Ketone body kinetics in humans: a mathematical model
ME Wastney, SE Hall and M Berman
A model has been developed to account for ketone body kinetics in man based
on data following bolus injections of [14C]acetoacetate (A) and
[14C]beta-OH butyrate (B) into normal humans in the postabsorptive state.
The model consists of separate compartments for blood A and B that are
linked by a tissue compartment in which rapid interconversion of the ketone
bodies occurs. The probability of movement from blood into this compartment
was assumed to be the same for both ketone bodies. Two slowly equilibrating
tissue compartments are required to account for the slow components in the
tracer data, and thus a five- compartment model is proposed. By modeling
the transient tracer data with the tracee in a steady state, ketone body
kinetics were defined in terms of the rapid interconversions of A and B,
and the slow exchanges of carbon within the tissues. The rates of release
of new A and B into blood, (UA and UB) were calculated. These rates were
less than the apparent production rates, PRA and PRB, as the PR's included
carbon atoms first released as the other ketone body. The exchange
constants between the compartments were determined in addition to the
fractional catabolic rates (FCR) and metabolic clearance rates (MCR) of A
and B. The initial space of distribution was 10 L and the mean values +/-
SD (n = 11), normalized to this volume, were UA = 6.4 +/- 5.0, UB = 8.8 +/-
8.0 (mumol L-1 min-1), FCRA = 0.226 +/- 0.142, FCRB = 0.188 +/- 0.124
(min-1), MCRA = 2.26 +/- 1.42, MCRB = 1.87 +/- 1.23 (L min-1) and PRA =
11.1 +/- 7.6, PRB = 12.7 +/- 10.0 (mumol L-1 min-1).
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
