APStracts 5:0051E, 1998.

Regional acetate kinetics and oxidation in human volunteers. Mittendorfer, B., L. S. Sidossis, E. Walser, D. L. Chinkes, R. R. Wolfe. Department of Surgery, University of Texas Medical Branch, Galveston, TX 77550. Department of Radiology, University of Texas Medical Branch, Galveston, TX 77550. Metabolism Unit, Shriners Burns Institute, Galveston, TX 77550

APStracts 5:0051E, 1998.

We have used a 3h primed continuous infusion of 1,2-13C-acetate in 5 fasted (24h) volunteers to quantify splanchnic and leg acetate metabolism (Protocol 1). Fractional extraction of acetate by both tissues was high (70%) and simultaneous uptake and release of acetate was 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. Further, we calculated whole-body labeled carbon recovery during 15h of 1,2-13C-acetate infusion in three volunteers (Protocol 2). Whole body acetate carbon recovery in CO2 was significantly higher (66.7+/-4.5%) after 15h of tracer infusion than after 3h. We conclude that acetate is rapidly taken up by the leg and splanchnic tissues and the percent recovery of CO2 from the 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 are similar to the whole-body CO2 recovery.

Received 14 August 1997; accepted in final form 16 February 1998.
APS Manuscript Number E382-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 9 March 1998