Transorgan fluxes in a porcine model reveal a central role for liver in acylcarnitine metabolism.

Abstract

Acylcarnitines are derived from mitochondrial acyl-CoA metabolism and have been associated with diet-induced insulin resistance. However, plasma acylcarnitine profiles have been shown to poorly reflect whole body acylcarnitine metabolism. We aimed to clarify the individual role of different organ compartments in whole body acylcarnitine metabolism in a fasted and postprandial state in a porcine transorgan arteriovenous model. Twelve cross-bred pigs underwent surgery where intravascular catheters were positioned before and after the liver, gut, hindquarter muscle compartment, and kidney. Before and after a mixed meal, we measured acylcarnitine profiles at several time points and calculated net transorgan acylcarnitine fluxes. Fasting plasma acylcarnitine concentrations correlated with net hepatic transorgan fluxes of free and C2- and C16-carnitine. Transorgan acylcarnitine fluxes were small, except for a pronounced net hepatic C2-carnitine production. The peak of the postprandial acylcarnitine fluxes was between 60 and 90 min. Acylcarnitine production or release was seen in the gut and liver and consisted mostly of C2-carnitine. Acylcarnitines were extracted by the kidney. No significant net muscle acylcarnitine flux was observed. We conclude that liver has a key role in acylcarnitine metabolism, with high net fluxes of C2-carnitine both in the fasted and fed state, whereas the contribution of skeletal muscle is minor. These results further clarify the role of different organ compartments in the metabolism of different acylcarnitine species.

• Authors: Marieke G Schooneman, Gabriella A M Ten Have, Naomi van Vlies, Sander M Houten, Nicolaas E P Deutz, Maarten R Soeters
• Journal: American journal of physiology. Endocrinology and metabolism (Am J Physiol Endocrinol Metab) Vol. 309 Issue 3 Pg. E256-64 (Aug 01 2015) ISSN: 1522-1555 [Electronic] United States
• PMID: 26037250 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 the American Physiological Society.

Chemical References

• Olive Oil
• Plant Oils
• acylcarnitine
• Palmitoylcarnitine
• Acetylcarnitine
• Carnitine

Topics

• Acetylcarnitine (blood, metabolism)
• Animals
• Carnitine (analogs & derivatives, biosynthesis, blood, metabolism)
• Catheters, Indwelling
• Crosses, Genetic
• Female
• Intestinal Mucosa (metabolism)
• Intestines (blood supply)
• Kidney (blood supply, metabolism)
• Lipid Metabolism
• Liver (blood supply, metabolism)
• Models, Biological
• Olive Oil
• Organ Specificity
• Palmitoylcarnitine (blood, metabolism)
• Plant Oils (administration & dosage, metabolism)
• Postprandial Period
• Sus scrofa