魚類の脂肪酸代謝 ＩＶ コイ血合肉ミトコンドリアにおけるβ‐酸化に基づく脂肪酸の減少率

Abstract

In order to elucidate the fatty acids responsible for the β-oxidation system in which fatty acids compete with one another, the relationship between the O2 uptake and the rate of fatty acid decrease based on β-oxidation and the characteristics of β-oxidation were studied in carp (Cyprinus carpio) dark muscle mitochondria. It was recognized that the endogenous fatty acids in mitochondria were only slightly decreased by β-oxidation and that the 16:0 acid added to the system progressively decreased with the increase of O2 uptake. Thus, the rate of fatty acid decrease could be expressed as follows: Rate of fatty acid decrease (%)=initial fatty acid-final fatty acid/initial fatty acid×100 The O2 uptake and the rate of fatty acid decrease were associated closely in the system, so we concluded that the rate of fatty acid decrease could be used as an index of the β-oxidation rate of fatty acid. Compared with the rates of decrease of various fatty acids in mixtures of fatty acids constituting fish oils, the rates of decrease of 18:1 and 16:1 acids were high and those of 16:0, 18:0, 18:2, 18:3, 20:4 and 22:6 acids were distinctly lower than those of monoenoic acids. Consequently, 18:1 and 16:1 acids were much more subject to β-oxidation in carp dark muscle mitochondria than other fatty acids.