Effects of volatile fatty acids on propionate metabolism and gluconeogenesis in caprine hepatocytes

• Published in: Journal of dairy science Vol. 70; no. 12; pp. 2504 - 2510
• Main Authors: Aiello, R.J, Armentano, L.E
• Format: Journal Article
• Language: English
• Published: United States Am Dairy Sci Assoc 01.12.1987; American Dairy Science Association
• Subjects: ACIDE GRAS VOLATILE; ACIDO GRASO VOLATIL; ALIMENTACION DE LOS ANIMALES; ALIMENTATION DES ANIMAUX; ANIMAL FEEDING; Animals; Butyrates - pharmacology; CAPRIN; CAPRINOS; Carnitine - pharmacology; Fatty Acids, Volatile - pharmacology; FOIE; FONCTION PHYSIOLOGIQUE; FUNCION FISIOLOGICA; GLICONEOGENESIS; Gluconeogenesis - drug effects; GLYCONEOGENESIS; GOATS; Goats - metabolism; HIGADO; In Vitro Techniques; Isobutyrates; LACTA; LACTACION; LACTATION; LIVER; Liver - cytology; Liver - drug effects; Liver - metabolism; Male; METABOLISM; METABOLISME; METABOLISMO; NEOGLYCOGENESE; PHYSIOLOGICAL FUNCTIONS; PRO0537PIONATE; PROPIONATES; Propionates - metabolism; PROPIONATOS; RUMIANTE; RUMINANT; RUMINANTS; Valerates - pharmacology; VOLATILE FATTY ACIDS
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(87)80318-1

Isolated caprine hepatocytes were incubated with fatty acids of various chain lengths. Short-chain fatty acids effects on rates of gluconeogenesis and oxidation from [2-14C]propionate were determined. Additions of glucose (2.5 mM) had no effect on hepatic [2-14C]propionate metabolism in the presence and absence of amino acids. A complete mixture of amino acids increased label incorporation from [2-14C]propionate into [14C]glucose by 22%. Butyrate inhibited [2-14C]propionate metabolism and increased the apparent Michaelis constant for [2-14C]propionate incorporation into [14C]glucose from 2.4 +/- 1.5 to 5.6 +/- .9 mM. Butyrate's effects on propionate were similar in the presence and absence of L-carnitine (1 mM). Isobutyrate, 2-methylbutyrate, and valerate (1.25 mM) had no effect on [14C]glucose production but decreased 14CO2 production to 57, 61, and 54% of the control [2-14C]propionate (1.25 mM). This inhibition on 14CO2 production was not competitive. Isovalerate had no effect on either [2-14C]propionate incorporation into glucose or CO2. An increase in ratio of [14C]glucose to 14CO2 from [2-14C]propionate demonstrated that short-chain fatty acids other than butyrate do not inhibit gluconeogenesis from propionate. In addition, fatty acids that generate a net synthesis of intracellular oxaloacetate may partition propionate carbons toward gluconeogenic rather than oxidative pathways in goat hepatocytes.