title: Inhibitory mechanism of l-glutamic acid on spawning of the starfish Patiria (Asterina) pectinifera.
abstract: l-Glutamic acid was previously identified as an inhibitor of spawning in the starfish Patiria (Asterina) pectinifera; this study examined how l-glutamic acid works. Oocyte release from ovaries of P. pectinifera occurred after germinal vesicle breakdown (GVBD) and follicular envelope breakdown (FEBD) when gonads were incubated ex vivo with either relaxin-like gonad-stimulating peptide (RGP) or 1-methyladenine (1-MeAde). l-Glutamic acid blocked this spawning phenotype, causing the mature oocytes to remain within the ovaries. Neither RGP-induced 1-MeAde production in ovarian follicle cells nor 1-MeAde-induced GVBD and FEBD was affected by l-glutamic acid. l-Glutamic acid may act through metabotropic receptors in the ovaries to inhibit spawning, as l-(+)-2-amino-4-phosphonobutyric acid, an agonist for metabotropic glutamate receptors, also inhibited spawning induced by 1-MeAde. Application of acetylcholine (ACH) to ovaries under inhibitory conditions with l-glutamic acid, however, brought about spawning, possibly by inducing contraction of the ovarian wall to discharge mature oocytes from the ovaries concurrently with GVBD and FEBD. Thus, l-glutamic acid may inhibit ACH secretion from gonadal nerve cells in the ovary. Mol. Reprod. Dev. 84: 246-256, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Biology, Faculty of Education, Tokyo Gakugei University, Koganei, Tokyo, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Mita
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D047288:Asterina / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000494:pharmacology*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D010053:Ovary / Q000166:cytology / Q000294:innervation / Q000378:metabolism*; D017470:Receptors, Glutamate / Q000378:metabolism*; D012098:Reproduction / Q000187:drug effects
chemical_list: D017470:Receptors, Glutamate; D018698:Glutamic Acid; D000109:Acetylcholine