Saturated fatty acids with different chain length as ketogenic substrates in the rat liver

RESUMO

Production of ketone bodies, activation of oxygen uptake and production of [14C] carbon dioxide due to fatty acids of various chain lengths were measured in the isolated perfused rat liver. As ketogenic substrates, the fatty acids investigated can be ordered in the following sequence strate < palmitate < laureate < decanoate < miristate < octanoate. For activation of oxygen consumptor, the same sequence is observed. A good linear correlation between the increase in oxygen uptake (deltaO2) and production of ketone bodies was found, with a mean deltaO2 of 0.66 mol per mol ketone bodies. This is a relatively low value when confronted with the known stoichiometry of ß-oxidation, and may be an indication of complexities in the metabolism of exogenously added fatty acids in the perfused liver