Received April 11, 2002
Accepted after revision June 11, 2002

Regional fat metabolism in human splanchnic and adipose tissues; the effect of exercise

¹ The Copenhagen Muscle Research Centre, Rigshospitalet section 7652, 9 Blegdamsvej, DK-2100, Copenhagen Ò, Denmark
² Department of Clinical Physiology, Bispebjerg Hospital, DK-2400, Copenhagen NV, Denmark
³ The Copenhagen Muscle Research Centre, University Hospital, section 7652, DK-2100, Copenhagen NV, Denmark

^* To whom correspondence should be addressed.

This study was conducted to investigate the role of splanchnic and adipose tissue in the regulation of fatty acid (FA) metabolism at rest, during 1 h of semi-recumbent cycle exercise at 60 % of maximal power output and 3 h of recovery. In six post-absorptive healthy volunteers catheters were placed in a radial artery, hepatic vein and a subcutaneous vein on the anterior abdominal wall. Whole body, and regional splanchnic and adipose tissue FA metabolism were measured by a constant infusion of the stable isotopes [U-¹³C]palmitate and [²H₅]glycerol and according to Fick's principle. The whole body rate of extracellular FA reesterification was similar at rest and during exercise (~290 µmol min^-1) and increased during recovery to a plateau of 390 µmol min^-1. FA and triacylglycerol (TAG) uptake by adipose tissue was undetectable, but a constant but small glycerol uptake of ~25 nmol (100 g)^-1 min^-1 was observed. From the FA taken up by the splanchnic area, 13 % was oxidized, 5-11 % converted to ketone bodies, and ~35 % incorporated in TAG released both at rest and at the third hour of recovery from exercise. Splanchnic FA reesterification could account for 51 % and 58 % of whole body extracellular FA reesterification, of which half was accounted for by TAG released from the splanchnic area, at rest and in recovery, respectively. In conclusion, in the post-absorptive state, adipose tissue contributes very little to extracellular FA reesterification and splanchnic reesterification can account for 50-60 %, implying that FA reesterification in other tissues is important. The extracellular FA reesterification rate does not change with exercise but is higher during recovery. Furthermore, the uptake of glycerol by adipose tissue indicates that adipose tissue can metabolize glycerol.

This article has been cited by other articles:

				C. Koutsari, D. A. Dumesic, B. W. Patterson, S. B. Votruba, and M. D. Jensen Plasma Free Fatty Acid Storage in Subcutaneous and Visceral Adipose Tissue in Postabsorptive Women Diabetes, May 1, 2008; 57(5): 1186 - 1194. [Abstract] [Full Text] [PDF]

				G. C. Henderson, J. A. Fattor, M. A. Horning, N. Faghihnia, M. Luke-Zeitoun, and G. A. Brooks Retention of intravenously infused [13C]bicarbonate is transiently increased during recovery from hard exercise J Appl Physiol, November 1, 2007; 103(5): 1604 - 1612. [Abstract] [Full Text] [PDF]

				G. C. Henderson, J. A. Fattor, M. A. Horning, N. Faghihnia, M. L. Johnson, T. L. Mau, M. Luke-Zeitoun, and G. A. Brooks Lipolysis and fatty acid metabolism in men and women during the postexercise recovery period J. Physiol., November 1, 2007; 584(3): 963 - 981. [Abstract] [Full Text] [PDF]

				G. A. Wallis, A. L. Friedlander, K. A. Jacobs, M. A. Horning, J. A. Fattor, E. E. Wolfel, G. D. Lopaschuk, and G. A. Brooks Substantial working muscle glycerol turnover during two-legged cycle ergometry Am J Physiol Endocrinol Metab, October 1, 2007; 293(4): E950 - E957. [Abstract] [Full Text] [PDF]

				J. W. Helge, B. Stallknecht, E. A. Richter, H. Galbo, and B. Kiens Muscle metabolism during graded quadriceps exercise in man J. Physiol., June 15, 2007; 581(3): 1247 - 1258. [Abstract] [Full Text] [PDF]

				F. Magkos, B. W. Patterson, B. S. Mohammed, and B. Mittendorfer A single 1-h bout of evening exercise increases basal FFA flux without affecting VLDL-triglyceride and VLDL-apolipoprotein B-100 kinetics in untrained lean men Am J Physiol Endocrinol Metab, June 1, 2007; 292(6): E1568 - E1574. [Abstract] [Full Text] [PDF]

				L. Frydelund-Larsen, T. Akerstrom, S. Nielsen, P. Keller, C. Keller, and B. K. Pedersen Visfatin mRNA expression in human subcutaneous adipose tissue is regulated by exercise Am J Physiol Endocrinol Metab, January 1, 2007; 292(1): E24 - E31. [Abstract] [Full Text] [PDF]

				M. Esbjornsson, J. Bulow, B. Norman, L. Simonsen, J. Nowak, O. Rooyackers, L. Kaijser, and E. Jansson Adipose tissue extracts plasma ammonia after sprint exercise in women and men J Appl Physiol, December 1, 2006; 101(6): 1576 - 1580. [Abstract] [Full Text] [PDF]

				Kevin. A. Jacobs, R. M. Krauss, J. A. Fattor, M. A. Horning, A. L. Friedlander, T. A. Bauer, T. A. Hagobian, E. E. Wolfel, and G. A. Brooks Endurance training has little effect on active muscle free fatty acid, lipoprotein cholesterol, or triglyceride net balances Am J Physiol Endocrinol Metab, September 1, 2006; 291(3): E656 - E665. [Abstract] [Full Text] [PDF]

				C. Koutsari and M. D. Jensen Thematic review series: Patient-Oriented Research. Free fatty acid metabolism in human obesity J. Lipid Res., August 1, 2006; 47(8): 1643 - 1650. [Abstract] [Full Text] [PDF]

				M. Hansen, R. Morthorst, B. Larsson, R. Dall, A. Flyvbjerg, M. H. Rasmussen, H. Orskov, M. Kjaer, and K. H. W. Lange No effect of growth hormone administration on substrate oxidation during exercise in young, lean men J. Physiol., September 15, 2005; 567(3): 1035 - 1045. [Abstract] [Full Text] [PDF]

				K. A. Jacobs, G. A. Casazza, S.-H. Suh, M. A. Horning, and G. A. Brooks Fatty acid reesterification but not oxidation is increased by oral contraceptive use in women J Appl Physiol, May 1, 2005; 98(5): 1720 - 1731. [Abstract] [Full Text] [PDF]

				L. H Enevoldsen, L Simonsen, I. A Macdonald, and J Bulow The combined effects of exercise and food intake on adipose tissue and splanchnic metabolism J. Physiol., December 15, 2004; 561(3): 871 - 882. [Abstract] [Full Text] [PDF]

				M. Sacchetti, B. Saltin, D. B Olsen, and G. van Hall High triacylglycerol turnover rate in human skeletal muscle J. Physiol., December 15, 2004; 561(3): 883 - 891. [Abstract] [Full Text] [PDF]

				V. B. Schrauwen-Hinderling, L. J. C. van Loon, R. Koopman, K. Nicolay, W. H. M. Saris, and M. E. Kooi Intramyocellular lipid content is increased after exercise in nonexercising human skeletal muscle J Appl Physiol, December 1, 2003; 95(6): 2328 - 2332. [Abstract] [Full Text]

				M. A. Febbraio, P. Ott, H. B. Nielsen, A. Steensberg, C. Keller, P. Krustrup, N. H. Secher, and B. K. Pedersen Hepatosplanchnic clearance of interleukin-6 in humans during exercise Am J Physiol Endocrinol Metab, August 1, 2003; 285(2): E397 - E402. [Abstract] [Full Text] [PDF]