title: Metabolism of R-beta-hydroxypentanoate and of beta-ketopentanoate in conscious dogs.
abstract: R-beta-Hydroxypentanoate and beta-ketopentanoate are homologues of physiological ketone bodies R-beta-hydroxybutyrate and acetoacetate. They derive from the oxidation in liver of the R-moiety of R,S-1,3-pentanediol, a potential nutrient. This report documents the metabolism of R-beta-hydroxypentanoate and beta-ketopentanoate in conscious dogs. Whether administered by bolus or constant infusion, the two substrates are interconverted and rapidly metabolized. When beta-ketopentanoate was infused at a rate corresponding to 75% of the dog's caloric requirement, the steady-state total plasma concentration of the two substrates was only 1.3 mM. Because the substrates are precursors of propionyl-CoA, we assayed the urinary concentrations of markers of propionic acidemia. Their accumulation was minor compared with what is observed in patients suffering from propionic acidemia. We conclude that, at least during short-term experiments, R-beta-hydroxypentanoate and beta-ketopentanoate are well metabolized in the dog without apparent intolerance to a large supply of propionyl-CoA.
authors.affiliation: Department of Nutrition, Université de Montréal, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Leclerc
authors.forename: C
authors.initials: C
authors.lastname: Des Rosiers
authors.forename: J A
authors.initials: JA
authors.lastname: Montgomery
authors.forename: J
authors.initials: J
authors.lastname: Brunet
authors.forename: L
authors.initials: L
authors.lastname: Ste-Marie
authors.forename: M W
authors.initials: MW
authors.lastname: Reider
authors.forename: C A
authors.initials: CA
authors.lastname: Fernandez
authors.forename: L
authors.initials: L
authors.lastname: Powers
authors.forename: F
authors.initials: F
authors.lastname: David
authors.forename: H
authors.initials: H
authors.lastname: Brunengraber
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004285:Dogs; D005217:Fat Emulsions, Intravenous; D008401:Gas Chromatography-Mass Spectrometry; D006018:Glycols / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010288:Parenteral Nutrition; D010421:Pentanoic Acids / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D011422:Propionates / Q000652:urine
chemical_list: D000214:Acyl Coenzyme A; D001786:Blood Glucose; D005217:Fat Emulsions, Intravenous; D006018:Glycols; D010421:Pentanoic Acids; D011422:Propionates; C009061:propionyl-coenzyme A; C091257:1,3-pentanediol; C029658:propionic acid