title: Possible functions of oxytocin/vasopressin-superfamily peptides in annelids with special reference to reproduction and osmoregulation.
abstract: Annetocin is an earthworm oxytocin-related peptide that we previously isolated from the whole body of a lumbricid earthworm Eisenia foetida. We have reported that annetocin induces egg-laying-like behaviors in E. foetida and a gnathobdellid leech, Whitmania pigra, when it is injected into the respective animals. The present study was undertaken to probe physiological functions of invertebrate oxytocin-vasopressin-superfamily peptides with special reference to reproductive and osmoregulatory events in which vertebrate peptides of this superfamily are involved. Annetocin, Lys-conopressin (a leech vasopressin-related peptide) and two analog peptides, [Tyr(3)]-annetocin ((3)Y-annetocin) and [Phe(3)]-annetocin ((3)F-annetocin), were compared for their activities to induce egg-laying-like behavior and to change body weight as a measure of water balance in the leech W. pigra. Injection of annetocin, Lys-conopressin, and (3)F-annetocin caused both egg-laying-like behavior and reduction of body weight in the animals, but (3)Y-annetocin induced neither. Furthermore, leeches in the non-breeding season responded to peptides less conspicuously than those in the breeding season. Such a concomitant induction of egg-laying-like behavior and body-weight reduction suggests that these two phenomena are unitary and might be accounted for by the fact that egg-laying in leeches and earthworms is accompanied by secretion of a large quantity of mucus, which should significantly contribute to body-weight loss. J. Exp. Zool. 284:401-406, 1999.
authors.affiliation: Department of Biological Science, Faculty of Science, Hiroshima University, Higashi Hiroshima 739-8526, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujino
authors.forename: T
authors.initials: T
authors.lastname: Nagahama
authors.forename: T
authors.initials: T
authors.lastname: Oumi
authors.forename: K
authors.initials: K
authors.lastname: Ukena
authors.forename: F
authors.initials: F
authors.lastname: Morishita
authors.forename: Y
authors.initials: Y
authors.lastname: Furukawa
authors.forename: O
authors.initials: O
authors.lastname: Matsushima
authors.forename: M
authors.initials: M
authors.lastname: Ando
authors.forename: H
authors.initials: H
authors.lastname: Takahama
authors.forename: H
authors.initials: H
authors.lastname: Satake
authors.forename: H
authors.initials: H
authors.lastname: Minakata
authors.forename: K
authors.initials: K
authors.lastname: Nomoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001835:Body Weight; D005260:Female; D007447:Invertebrate Hormones / Q000502:physiology*; D007865:Leeches / Q000502:physiology*; D008969:Molecular Sequence Data; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000502:physiology; D010446:Peptide Fragments / Q000502:physiology*; D010456:Peptides, Cyclic / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D007447:Invertebrate Hormones; D010446:Peptide Fragments; D010456:Peptides, Cyclic; C076621:conopressin G; C085335:annetocin; D010121:Oxytocin