Human forearm arteriovenous differences of carnitine, short-chain acylcarnitine and long-chain acylcarnitine.
1. Forearm arterial and venous concentrations of free carnitine, short-chain acylcarnitine, long-chain acylcarnitine, glucose, lactate, pyruvate, alanine, non-esterified fatty acids, glycerol, 3-hydroxybutyrate and acetoacetate were measured in fasted adult subjects. 2. In all subjects there was net uptake of short-chain acylcarnitine, 3-hydroxybutyrate and acetoacetate and net release of free carnitine and non-esterified fatty acids. The arteriovenous differences of the other metabolites were not consistent. 3. These observations support the concept that short-chain acylcarnitine (largely acetylcarnitine) contributes to the flux of metabolic fuels from the liver to muscle in the fasted state, although to a limited extent in comparison with 3-hydroxybutyrate (less than 5% on a molar basis).
Bartlett
K
K
Department of Child Health, Medical School, University of Newcastle-upon-Tyne, U.K.
Bhuiyan
A K
AK
Aynsley-Green
A
A
Butler
P C
PC
Alberti
K G
KG
D020155:3-Hydroxybutyric Acid; D000090:Acetoacetates / Q000378:metabolism; D000108:Acetylcarnitine / Q000097:blood* / Q000378:metabolism; D000328:Adult; D002087:Butyrates / Q000378:metabolism; D002331:Carnitine / Q000031:analogs & derivatives* / Q000097:blood* / Q000378:metabolism; D005215:Fasting; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005542:Forearm; D006801:Humans; D006885:Hydroxybutyrates / Q000378:metabolism
D000090:Acetoacetates; D002087:Butyrates; D005232:Fatty Acids, Volatile; D006885:Hydroxybutyrates; C016635:acetoacetic acid; D000108:Acetylcarnitine; D002331:Carnitine; D020155:3-Hydroxybutyric Acid