title: Cardioinhibitory peptides from Limulus polyphemus: modulation of the neurogenic heart.
abstract: Four neuropeptides have been isolated and sequenced from acetone extracts of brains of the horseshoe crab Limulus polyphemus. They belong to a newly discovered peptide family in invertebrates. A possible role of the four peptides from Limulus as cardioregulatory neurotransmitters has been tested on the isolated Limulus heart. Three of the peptides (DEGHKMLYFamide, GHSLLHFamide, and PDHHMMYFamide) produce dose-dependent decreases in both amplitude and rate of the heart contractions, whereas DHGNMLYFamide reduces only the amplitude of the heartbeat. All four peptides differ in threshold, potency and duration of their effects.
authors.affiliation: Institut für Biologie II (Zoologie), Aachen, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Gaus
authors.forename: M
authors.initials: M
authors.lastname: Casaretto
authors.forename: H
authors.initials: H
authors.lastname: Stieve
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006737:Horseshoe Crabs / Q000502:physiology*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology / Q000502:physiology*; D009842:Oligopeptides / Q000502:physiology; D009994:Osmolar Concentration; D013997:Time Factors
chemical_list: D060829:Arthropod Proteins; D009479:Neuropeptides; D009842:Oligopeptides; C089491:aspartyl-glutamyl-glycyl-histidyl-lysyl-methionyl-leucyl-tyrosyl-phenylalaninamide; C089494:aspartyl-histidyl-glycyl-asparaginyl-methionyl-leucyl-tyrosyl-phenylalaninamide; C089492:glycyl-histidyl-seryl-leucyl-leucyl-histidyl-phenylalaninamide; C089493:prolyl-aspartyl-histidyl-histidyl-methionyl-methionyl-tyrosyl-phenylalaninamide