Glucogenic pathway for acetone metabolism in the lactating cow
Black, A.L.; Luick, J.R.; Lee, S.L.; Knox, K.
American Journal of Physiology 222(6): 1575-1580
1972
ISSN/ISBN: 0002-9513 PMID: 5063962 Document Number: 56013
The possibility for conversion of even-chain fatty acids to glucose via ketone bodies was investigated in lactating cows injected i/v with 14C-labelled acetone, beta-hydroxybutyrate (BHB), pyruvate or butyrate. Data were obtained on the extent of labelling of carbohydrates and amino acids and the intramolecular labelling pattern in glutamate and glucose. Carbon from acetone followed a glucogenic pathway, giving rise to net synthesis of oxalacetate and in many respects acetone metabolism resembled the utilization of pyruvate. BHB, on the other hand, did not follow a glucogenic pathway, resembling more closely butyrate in its metabolism. Since BHB is the major ketone body in ruminants, and only very small amounts of acetone are formed, it was concluded that gluconeogenesis from ketone bodies is very limited and does not provide a route for synthesis of significant amounts of glucose from even-chain fatty acids.