THE DISTRIBUTION OF METHIONINE‐ENKEPHALIN AND LEUCINE‐ENKEPHALIN IN THE BRAIN AND PERIPHERAL TISSUES
THE DISTRIBUTION OF METHIONINE‐ENKEPHALIN AND LEUCINE‐ENKEPHALIN IN THE BRAIN AND PERIPHERAL TISSUES
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DOI：
10.1111/j.1476-5381.1997.tb06829.x
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发表时间：
1997-02
影响因子：
7.3
通讯作者：
J. Hughes;H. Kosterlitz;T. Smith
中科院分区：
文献类型：
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作者：
J. Hughes;H. Kosterlitz;T. Smith
1描述了一种从脑和其他组织中快速提取阿片肽的方法。该方法基于组织的酸浸提，然后将浸提液吸附到Amberlite XAD-2树脂上。用甲醇洗脱将脑啡肽和α-内啡肽与β-内啡肽分离。2通过我们的方法从几个物种的大脑和肠道中分离出的阿片肽活性的90%以上是由于甲硫氨酸和亮氨酸脑啡肽。相反，从垂体中恢复的主要阿片肽活性是由于分子量大得多的肽。重量比脑啡肽更强3.脑提取物中存在一种阿片肽，其性质与已知的内啡肽或脑啡肽不同。这种肽，称为ε-内啡肽，具有表观摩尔。重量700至1200;它构成了我们提取物中总阿片活性的5%至10%。4甲硫氨酸-脑啡肽和亮氨酸-脑啡肽的差异测定通过用溴化氰破坏甲硫氨酸-脑啡肽活性或通过薄层色谱法分离肽来进行。[5]蛋氨酸脑啡肽与亮氨酸脑啡肽的比例在不同脑区有很大差异。亮氨酸脑啡肽的最高比例在大脑皮层和海马中发现。6活体脑的甲醛灌流和固定对脑啡肽含量无明显影响，表明蛋白水解分解并不是提取这些肽的主要问题。7这表明脑啡肽可能在脑和外周组织中具有神经递质作用，并且甲硫氨酸和亮氨酸脑啡肽可能有助于单独的神经元功能。
1 A method is described for the rapid extraction of opioid peptides from the brain and other tissues. The method is based on acid extraction of tissues followed by adsorption of the extract onto Amberlite XAD‐2 resin. Elution with methanol separates the enkephalins and α‐endorphin from β‐endorphin. 2 Over 90% of the opioid peptide activity isolated from brain and gut of several species by our method was due to methionine‐ and leucine‐enkephalin. In contrast, the major opioid peptide activity recovered from the pituitary was due to peptides of much greater mol. wt. than the enkephalins. 3 An opioid peptide with properties unlike those of the known endorphins or enkephalins was present in brain extracts. This peptide, termed ∈‐endorphin, has an apparent mol. wt. of 700 to 1200; it constituted between 5 to 10% of the total opioid activity in our extracts. 4 A differential assay of methionine‐ and leucine‐enkephalin was made either by destroying methionine‐enkephalin activity with cyanogen bromide or by separating the peptides by thin layer chromatography. 5 The ratio of methionine‐enkephalin to leucine‐enkephalin varied greatly in different brain regions. The highest proportions of leucine‐enkephalin were found in the cerebral cortex and hippocampus. 6 Formaldehyde perfusion and fixation of the brain in vivo had no significant effect on the brain content of enkephalin, indicating that proteolytic breakdown is not a major problem in the extraction of these peptides. 7 It is suggested that the enkephalins may have a neurotransmitter role in both brain and peripheral tissues and that methionine‐ and leucine‐enkephalin may subserve separate neuronal functions.