FMRFamide, a Cardioexcitatory Neuropeptide of Molluscs: An Agent in Search of a Mission
FMRFamide, a Cardioexcitatory Neuropeptide of Molluscs: An Agent in Search of a Mission
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FMRFamide，软体动物的心脏兴奋性神经肽：寻找使命的代理人
DOI：
10.1093/icb/19.1.163
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发表时间：
1979
影响因子：
2.6
通讯作者：
D. Price
中科院分区：
文献类型：
--
作者：
M. Greenberg;D. Price
软体动物神经节的水提物具有心脏兴奋活性，这与通常的神经体液：5-羟色胺、乙酰胆碱或多巴胺无关。形态学、生理学和生化研究表明，这种心脏兴奋是由少数未识别的神经激素引起的，主要是多肽。摘要本文分离、纯化、表征并合成了一种有效成分，该成分来自于双瓣菊（Macrocallista nimbosa, Bivalvia）中央神经节池提取物。该物质先前被指定为峰C，是一种四肽酰胺：苯丙酰-蛋氨酸-精氨酸-苯丙氨酸酰胺（Phe-Met-Arg-Phe-NH2; FMRFamide）。低浓度的FMRFamide（阈值：10−9-10−8M）诱导离体静息双壳类心脏的节律性活动，并增强已经跳动的双壳类心脏的收缩力和频率。该肽还能引起非心脏类软体动物肌肉的收缩，尤其是海螺（一种敏感的测定对象）的管状量角器。FMRFamide对雇佣兵心脏的作用似乎是由腺苷3',5'-单磷酸腺苷（环状AMP）介导的。C活性峰值出现在所有主要软体动物类别的所有测试物种中；但我们还不知道是否所有的峰C′；我们是famide。FMRFamide是一种神经分泌产物还有待确定，其在软体动物中的正常生理作用也有待确定。尽管如此，我们认为FMRFamide与其他神经肽一起被释放到血淋巴中，对内脏肌肉的张力、节律性和兴奋性提供长期的维持和调节。
Aqueous extracts of molluscan ganglia have cardioexcitatory activity that is not attributable to the usual neurohumors: 5-hydroxytryptamine, acetylcholine or dopamine. Morphological, physiological and biochemical studies have suggested that this cardioexcitation is caused by a handful of unidentified neurohormones, mostly polypeptides. One of the active components of extracts of the pooled central ganglia of Macrocallista nimbosa (Bivalvia) has now been isolated, purified, characterized and synthesized. This substance, previously designated peak C, is a tetrapeptide amide: phenylalanyl-methionyl-arginyl-phenylalanine amide (Phe-Met-Arg-Phe-NH2; FMRFamide). Low concentrations of FMRFamide (threshold: 10−9–10−8M) induce rhythmical activity in isolated quiescent bivalve hearts and augment the force and frequency of contraction of those already beating. The peptide also produces contractures of non-cardiac molluscan muscles, including especially the radula protractor of the whelk, Busycon contrarium , a sensitive assay object. The effects of FMRFamide on Mercenaria mercenaria hearts appear to be mediated by adenosine 3', 5'-monophosphate (cycwic AMP). Peak C activity occurs in all species tested in all the major molluscan classes; but we do not yet know whether all Peak C';s are FMRFamide. That FMRFamide is a neurosecretory product has still to be established, and its normal physiological role in molluscs has yet to be defined. Nevertheless, we suppose that, together with other neuropeptides, FMRFamide is released into the hemolymph to provide long-term maintenance and regulation of tone, rhythmicity and excitability of visceral muscle.