Groome J R, Townley M A, Watson W H
Marine Biological Laboratory, Woods Hole, Massachusetts 02543.
Biol Bull. 1994 Jun;186(3):309-18. doi: 10.2307/1542277.
The actions of FMRFamide-related peptides (FaRPs) on the neurogenic heart of the horseshoe crab, Limulus polyphemus, were investigated. Excitatory chronotropic effects were produced by application of TNRNFLRFamide, SDRNFLRFamide, GYNRS-FLRFamide, or pQDPFLRFamide to the intact heart preparation. Effects were dose-dependent with a threshold of 10(-9) M or less. TNRNFLRFamide and SDRNFLRFamide increased the burst rate of the isolated Limulus cardiac ganglion. Synthetic FaRPs produced inotropic excitation of the heartbeat as well. GYNRSFLRFamide, TNRNFLRFamide, SDRNFLRFamide, and pQDPFLRFamide increased heart contraction strength at a threshold dose of approximately 10(-8) M. TNRNFLRFamide and SDRNFLRFamide enhanced electrically evoked contractions of the Limulus myocardium, elicited contracture in some preparations, and increased the excitability of cardiac muscle fibers. The presence of cardioactive FaRPs in the Limulus central nervous system was suggested by reverse phase HPLC of acidified methanol extracts of Limulus nervous tissue. Four peaks of FaRP-like bioactivity were detected with the Busycon radula protractor muscle bioassay. These peaks also contained FaRP-like immunoreactivity. Two of these partially purified peaks produced excitatory chronotropic effects on the intact Limulus heart preparation similar to those produced by synthetic FaRPs.
研究了FMRF酰胺相关肽（FaRPs）对鲎（Limulus polyphemus）神经源性心脏的作用。将TNRNFLRF酰胺、SDRNFLRF酰胺、GYNRS - FLRF酰胺或pQDPFLRF酰胺应用于完整心脏标本时，会产生正性变时效应。效应呈剂量依赖性，阈值为10^(-9) M或更低。TNRNFLRF酰胺和SDRNFLRF酰胺增加了分离的鲎心脏神经节的爆发频率。合成的FaRPs也产生了心跳的变力性兴奋。GYNRSFLRF酰胺、TNRNFLRF酰胺、SDRNFLRF酰胺和pQDPFLRF酰胺在约10^(-8) M的阈值剂量下增加了心脏收缩强度。TNRNFLRF酰胺和SDRNFLRF酰胺增强了鲎心肌的电诱发收缩，在一些标本中引起挛缩，并增加了心肌纤维的兴奋性。通过对鲎神经组织酸化甲醇提取物的反相高效液相色谱分析，提示鲎中枢神经系统中存在具有心脏活性的FaRPs。用Busycon齿舌量角器肌肉生物测定法检测到四个具有FaRP样生物活性的峰。这些峰也含有FaRP样免疫反应性。其中两个部分纯化的峰对完整的鲎心脏标本产生了类似于合成FaRPs的正性变时效应。
