B. Mittendorfer et al., REGIONAL ACETATE KINETICS AND OXIDATION IN HUMAN VOLUNTEERS, American journal of physiology: endocrinology and metabolism, 37(6), 1998, pp. 978-983
We have used a 3-h primed continuous infusion of [1,2-C-13]acetate in
five fasted (24 h) volunteers to quantify splanchnic and leg acetate m
etabolism (protocol 1). Fractional extraction of acetate by both tissu
es was high (similar to 70%), and simultaneous uptake and release of a
cetate were observed. Labeled carbon recovery in CO2 was 37.9 +/- 2.3%
at the whole body level, 37.7 +/- 1.5% across the splanchnic bed, and
37.3 +/- 2.9% across the leg. Furthermore, we calculated whole body l
abeled carbon recovery during 15 h of [1,2-C-13]acetate infusion in th
ree volunteers (protocol 2). Whole body acetate carbon recovery in CO2
was significantly higher (66.7 +/- 4.5%) after 15 h of tracer infusio
n than after 3 h. We conclude that acetate is rapidly taken up by the
leg and splanchnic tissues and that the percent recovery of CO2 from t
he oxidation of acetate is heavily dependent on the length of acetate
tracer infusion. In the postabsorptive state, labeled carbon recovery
from acetate across the leg and the splanchnic region is similar to th
e whole body CO2 recovery.