title: Cardioactive peptides isolated from the brain of a Japanese octopus, Octopus minor.
abstract: Octopus cardioactive peptides (Ocp-1: Gly-D-Phe-Gly-Asp, and Ocp-3: Gly-Ser-Trp-Asp) were isolated from brain extracts of the octopus, Octopus minor, using the isolated systemic heart as a bioassay. These peptides showed both positive chronotropic and inotropic effects on the heart. The stereoisomers at position 2 were also isolated, but their activities were only 1/10(3)-1/10(4) those of the corresponding isomers. The presence of the peptides in the systemic heart was confirmed by time-of-flight mass spectrometry (MS) and tandem MS analysis. The results suggested that Ocp-1 and Ocp-3 might be involved in excitatory control of the octopus cardiovascular system as neuropeptides and/or neurohormones.
authors.affiliation: Suntory Institute for Bioorganic Research, 618-8503, Osaka, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Iwakoshi
authors.forename: M
authors.initials: M
authors.lastname: Hisada
authors.forename: H
authors.initials: H
authors.lastname: Minakata
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D049831:Octopodiformes; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010455:Peptides