Synthesis of very long chain (up to 36 carbon) tetra, penta and hexaenoic fatty acids in retina.
Synthesis of very long chain (up to 36 carbon) tetra, penta and hexaenoic fatty acids in retina.
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视网膜中极长链（最多 36 个碳）四、五和六烯脂肪酸的合成。
DOI：
10.1042/bj2490191
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
M. Aveldaño
中科院分区：
文献类型：
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作者：
N. Rotstein;M. Aveldaño
用[14C]乙酸酯在牛视网膜中合成了超长链(C24~C36)多不饱和(四、五和六个双键)脂肪酸(VLCPUFA)。一方面饱和(主要是棕榈酸酯)，另一方面是多烯(主要是VLCPUFA)，结合了脂类中的大部分标签。磷脂酰胆碱(PC)是最高标记的脂类，因为两种类型的14C标记的脂肪酸，特别是这一新系列的VLCPUFA，都集中在这种磷脂中。在PC的超长链四、五和六烯酸中发现了来自[14C]乙酸酯的放射性。20：4(n-6)、20：5(n-3)、22：5(n-6)和22：6(n-3)的标记物明显低于这些系列中较长的多烯，说明VLCPUFA是由这些多烯连续延伸原位合成的，这些多烯预先存在于视网膜脂质中。在与[14C]醋酸酯孵育后的视网膜中分离的各种亚细胞组分(包括胞浆、微粒体、线粒体和光感受器膜)中，PC的VLCPUFA的标记很高，即使在相对较短的孵育间隔内也是如此。这些结果表明，不仅含有VLCPUFA的PC的合成以及膜之间的运输都是视网膜中非常活跃的过程。
The synthesis of very long chain (C24 to C36) polyunsaturated (four, five and six double bonds) fatty acids (VLCPUFA) is investigated in bovine retina using [14C]acetate. Saturates on the one hand (mainly palmitate), and polyenes on the other (mainly VLCPUFA), incorporate most of the label found in lipids. Phosphatidylcholine (PC) is the most highly labelled lipid class, since both types of 14C-labelled fatty acids, but especially this novel series of VLCPUFA, are concentrated in this phospholipid. Radioactivity from [14C]acetate is found in very long chain tetra, penta and hexaenoic fatty acids of PC. The labelling of 20:4(n - 6), 20:5(n - 3), 22:5(n - 6) and 22:6(n - 3) is much lower than that of longer polyenes of each of these series, indicating that VLCPUFA are synthesized in situ by successive elongations of the above polyenes, pre-existing in retina lipids. In various subcellular fractions isolated from retinas after incubations with [14C]acetate (including cytosol, microsomes, mitochondria and photoreceptor membranes), the labelling of the VLCPUFA of PC is very high, even at relatively short intervals of incubation. The results suggest that not only the synthesis but also the intracellular traffic among membranes of VLCPUFA-containing species of PC are very active processes in the retina.