Demaison L, Dubois F, Apparu M, Mathieu J P, Vidal M, Comet M, Cuchet P
University of Sciences, Technology and Medicine, Grenoble, France.
J Nucl Med. 1988 Jul;29(7):1230-6.
Methylated fatty acids labeled with radioactive iodine have been proposed as a means of studying regional myocardial uptake of fatty acids in man. To investigate the methylated fatty acid that is best adapted for an assessment of uptake, we have studied the influence of the number and the position of the methyl groups of IFA intracellular metabolism; 16-iodo-2-methyl-hexadecanoic (mono-alpha), 16-iodo-2,2-methyl hexadecanoic (di-alpha), 16-iodo-3-methyl-hexadecanoic (mono-beta), and 16-iodo-3,3-methyl-hexadecanoic (di-beta) acids were injected into the coronary arteries of isolated rat hearts. Intracellular analysis shows that the degradation of mono-alpha was always lower than that of IHA and the storage was always much higher. The differences between mono-beta and IHA were similar to those observed with mono-alpha, but were much more pronounced. With the two dimethylated IFAs there was an inhibition of both oxidation and esterification which led to an accumulation of free FAs in myocardial cells. In conclusion, mono-beta, di-alpha, and di-beta are potentially suitable for studying the cellular uptake of IFA since all of them, and particularly the dimethylated IFAs, have a low oxidation rate.
用放射性碘标记的甲基化脂肪酸已被提议作为研究人体心肌脂肪酸区域摄取的一种方法。为了研究最适合评估摄取的甲基化脂肪酸，我们研究了甲基数量和位置对碘代脂肪酸（IFA）细胞内代谢的影响；将16-碘-2-甲基十六烷酸（单α）、16-碘-2,2-二甲基十六烷酸（二α）、16-碘-3-甲基十六烷酸（单β）和16-碘-3,3-二甲基十六烷酸（二β）注入离体大鼠心脏的冠状动脉。细胞内分析表明，单α的降解始终低于碘代十六烷酸（IHA），且储存量始终高得多。单β与IHA之间的差异与单α观察到的相似，但更为明显。对于两种二甲基化的IFA，氧化和酯化均受到抑制，导致心肌细胞中游离脂肪酸积累。总之，单β、二α和二β可能适合用于研究IFA的细胞摄取，因为它们所有，尤其是二甲基化的IFA，氧化率都很低。
