RAT-BRAIN PHOSPHATIDYL-N,N-DIMETHYLETHANOLAMINE IS RICH IN POLY-UNSATURATED FATTY-ACIDS
RAT-BRAIN PHOSPHATIDYL-N,N-DIMETHYLETHANOLAMINE IS RICH IN POLY-UNSATURATED FATTY-ACIDS
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DOI：
10.1111/j.1471-4159.1985.tb04064.x
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发表时间：
1985-01-01
影响因子：
4.7
通讯作者：
WURTMAN, RJ
中科院分区：
文献类型：
--
作者：
TACCONI, M;WURTMAN, RJ
从大鼠脑中提纯了磷脂酰乙醇胺(PDME)，它是磷脂酰乙醇胺(PE)甲基化生成磷脂酰胆碱(PG)的中间体。多不饱和脂肪酸(PUFAs)在PDME中所占比例(29.8%)与PE(27.7%)相近，远高于PC(2.8%)。与PE中的多不饱和脂肪酸一样，PDME中的多不饱和脂肪酸主要是花生四烯酸(20：4)和二十二碳六烯酸(22：6)。建立了一种从脑中提纯的PDME的同位素定量方法，在环己胺存在下，将CH3I中的一个氚甲基转移到PDME上，形成[~3H]PC，然后计算PC的放射性。用此法测得大鼠脑内PDME浓度为(33.0±-)。1.8µg/g脑)与用定量GLC分析其FAs(36.9.+-)非常相似。1.8µg/g)。还分析了大鼠脑突触体PE和PC中的FA；突触体中存在的PDME太少，无法进行类似的分析。不饱和脂肪酸在突触体PE中所占比例(43.4%比27.7%)甚至高于全脑PE中的比例。由于突触体具有很高的磷脂酰基-N-甲基转移酶的活性，这种酶复合体使PE甲基化形成PC，这种酶可能在神经末梢产生一个特殊的PC池，富含多不饱和脂肪酸，可能具有独特的生理功能。
Phosphatidyl-N,N-dimethylethanolamine (PDME), an intermediate in the formation of phosphatidylcholine (PG) by the sequential methylation of phosphatidylethanolamine (PE), was purified from rat brain and its fatty acid (FA) composition compared with those of brain PC and PE. The proportion of polyunsaturated fatty acids (PUFAs) in the PDME (29.8%) was similar to that of PE (27.7%) and much greater than in PC (2.8%). Like the PUFAs of PE, the major PUFAs found in PDME were arachidonic acid (20:4) and docosahexaenoic acid (22:6). An isotopic method was developed to quantify the PDME purified from brain; a tritiated methyl group from CH3I was transferred to the PDME in the presence of cyclohexylamine to form [3H]PC, and the radioactivity of the PC was then counted. The concentration of rat brain PDME obtained using this method (33.0 .+-. 1.8 .mu.g/g brain) was very similar to that obtained using quantitative GLC analysis of its FAs (36.9 .+-. 1.8 .mu.g/g). The FAs in the PE and PC of rat brain synaptosomes were also analyzed; too little PDME was present in synaptosomes to permit similar analysis. The percentage of unsaturated FAs insynaptosomal PE was even higher (43.4 vs. 27.7) than that in PE prepared from whole brain. Since synaptosomes have a very high activity of phosphatidyl-N-methyltransferase, the enzyme complex that methylates PE to form PC, this enzyme may serve, in nerve endings, to produce a particular pool of PC, rich in PUFAs, which may have a distinct physiological function.