Robinson B S, Johnson D W, Poulos A
Department of Chemical Pathology, Adelaide Medical Centre for Women and Children, South Australia.
Biochem J. 1990 Apr 15;267(2):561-4. doi: 10.1042/bj2670561.
Rat brain was recently found to contain polyenoic very-long-chain fatty acids (VLCFA) belonging to the n-3 and n-6 series with four, five and six double bonds and even-carbon chain lengths from 24 to 38 [Robinson, Johnson & Poulos (1990) Biochem. J. 265, 763-767]. In the present paper, the metabolism in vivo of hexacosatetraenoic acid (C26:4,n-6) was studied in neonatal rat brain. Rats were injected intracerebrally with [1-14C]C26:4,n-6 and the labelled metabolites were examined after 4 h. Radioactivity was detected mainly in non-esterified fatty acids, with smaller amounts in other neutral lipids and phospholipids. Radiolabelled fatty acid products included C28-36 tetraenoic and C26-28 pentaenoic VLCFA formed by elongation and desaturation of the substrate, and C14-24 saturated, C16-24 monoenoic, C18-24 dienoic, C18-22 trienoic and C20-24 tetraenoic fatty acids formed from released [1-14C]acetate either by synthesis de novo or by elongation of endogenous fatty acids. The data suggest that polyenoic VLCFA are synthesized in brain from shorter-chain precursor fatty acids and undergo beta-oxidation.
最近发现大鼠脑中含有属于n-3和n-6系列的多烯超长链脂肪酸（VLCFA），具有四个、五个和六个双键，碳链长度为24至38的偶数碳链[罗宾逊、约翰逊和普洛斯（1990年）《生物化学杂志》265卷，763 - 767页]。在本文中，研究了新生大鼠脑中二十六碳四烯酸（C26:4，n-6）的体内代谢。给大鼠脑内注射[1-14C]C26:4，n-6，4小时后检查标记的代谢产物。放射性主要在非酯化脂肪酸中检测到，在其他中性脂质和磷脂中的含量较少。放射性标记的脂肪酸产物包括由底物的延长和去饱和形成的C28 - 36四烯酸和C26 - 28五烯酸VLCFA，以及由释放的[1-14C]乙酸通过从头合成或内源性脂肪酸的延长形成的C14 - 24饱和脂肪酸、C16 - 24单烯酸、C18 - 24二烯酸、C18 - 22三烯酸和C20 - 24四烯酸。数据表明多烯VLCFA在脑中由较短链的前体脂肪酸合成并经历β-氧化。
