PLATYHELMINTH FMRFAMIDE-RELATED PEPTIDES (FARPS) CONTRACT SCHISTOSOMA-MANSONI (TREMATODA, DIGENEA) MUSCLE-FIBERS IN-VITRO
PLATYHELMINTH FMRFAMIDE-RELATED PEPTIDES (FARPS) CONTRACT SCHISTOSOMA-MANSONI (TREMATODA, DIGENEA) MUSCLE-FIBERS IN-VITRO
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DOI：
10.1017/s0031182000080707
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发表时间：
1994-11-01
期刊：
影响因子：
2.4
通讯作者：
PAX, RA
中科院分区：
文献类型：
--
作者：
DAY, TA;MAULE, AG;PAX, RA
软体动物的FMRFamide和两个新近发现的扁虫FMRFamide相关多肽(FARPs)，即来自扩张莫尼齐斯的GNFFRFamide和来自陆栖涡虫Artioposthia triangulata的RYIRFamide，在体外引起曼氏血吸虫单个肌肉纤维的剂量依赖性收缩。被测试的最强的FARP是涡虫肽RYIRFamide，它在10(-9)到10(-7)M之间产生浓度依赖效应，FMRFamide和GNFFRFamide的作用较弱，分别在10(-8)-10(-6)M和10(-7)-10(-5)M之间引起收缩。这些多肽的收缩作用均可被1MU的FMR-D-Famide所阻断。FMRF游离酸不能引起肌肉纤维收缩。去掉钙离子和0.5 mU的EGTA，FARP引起的收缩不发生。加入胞外培养基中。钙通道阻滞剂尼卡地平、维拉帕米或地尔硫卓不能阻断FARP引起的收缩，但尼卡地平能阻断高KF引起的这些纤维的收缩。这些数据表明血吸虫肌肉纤维上存在FARP受体，并证明了它们调节肌肉收缩的能力。这些内源性扁虫多肽对血吸虫肌肉的作用首次证明了任何可能的神经递质对扁虫肌肉的直接兴奋作用，并确立了FARP在吸虫神经肌肉传递中的作用。此外，它还提供了首次证据表明，肽能神经系统是寄生颈椎动物化学治疗攻击的合理靶点。
Molluscan FMRFamide and two recently discovered platyhelminth FMRFamide-related peptides (FaRPs), GNFFRFamide from the cestode Moniezia expansa and RYIRFamide from the terrestrial turbellarian Artioposthia triangulata, cause dose-dependent contractions of individual muscle fibres from Schistosoma mansoni in vitro. The most potent FaRP tested was the turbellarian peptide RYIRFamide, which produced a concentration-dependent effect between 10(-9) and 10(-7) M. FMRFamide and GNFFRFamide were less potent, inducing contractions between 10(-8)-10(-6) M and 10(-7)-10(-5) M respectively. The contractile effect of each of these peptides was blocked by the presence of 1 mu M FMR-D-Famide. FMRF free acid did not elicit contraction of the muscle fibres. The FaRP-induced contractions did not occur if the Ca2+ was omitted and 0.5 mu M EGTA. was added to the extracellular medium. The FaRP-induced contractions were not blocked by the Ca2+ channel blockers nicardipine, verapamil or diltiazem, although high Kf-induced contractions of these fibres were blocked by nicardipine. These data indicate the presence of FaRP receptors on schistosome muscle fibres and demonstrate their ability to mediate muscle contraction. The action of these endogenous flatworm peptides on schistosome muscle is the first demonstration of a direct excitatory effect of any putative neurotransmitter on the muscle of a flatworm, and establishes a role for FaRPs in neuromuscular transmission in trematodes. In addition, it provides the first evidence that the peptidergic nervous system is a rational target for chemotherapeutic attack in parasitic platyhelmiths.