title: Gonadotropins and Growth Hormone Family Characterization in an Endangered Siluriform Species, Steindachneridion parahybae (Pimelodidae): Relationship With Annual Reproductive Cycle and Induced Spawning in Captivity.
abstract: The aim of this study was to identify and characterize pituitary cells of Steindachneridion parahybae females in captivity, highlighting the possible relationship with reproductive disorders at this level, since this species shows oocyte final maturation, ovulation and spawning dysfunction in captivity. The localization and distribution of growth hormone (GH), prolactin (PRL), somatolactin (SL), β-luteinizing hormone (β-LH), and β-follicle stimulating hormone (β-FSH) immunoreactive (-ir) cells in the adenohypophysis was studied by immunohistochemical and Western blot methods. In addition, cellular morphometric analyses and semi-quantification of ir-cells optical density (OD) during the annual reproductive cycle and after artificial induced spawning (AIS) were performed. Results showed that the distribution and general localization of pituitary cell types were similar to that of other teleost species. However, the morphometrical study of adenohypophysial cells showed differences along the reproductive cycle and following AIS. In general, females at the vitellogenic stage presented greater OD values for GH, PRL and SL than at other maturation stages (previtellogenic and regression stages), probably indicating an increased cellular activity during this stage. Conversely, β-LH OD did not vary during the annual reproductive cycle. After AIS, β-LH, SL and GH ir-cells showed an increase in OD values suggesting a possible involvement on oocyte final maturation, ovulation and spawning or a feedback control on the brain-pituitary-gonads axis. Reproductive dysfunction in S. parahybae females in captivity may be due to alteration of the synthesis pathways of β-LH. In addition, GH family of hormones could modulate associated mechanisms that influence the reproductive status in this species.
authors.affiliation: Departamento De Fisiologia, Instituto De Biociências, Universidade De São Paulo, Rua Do Matão, Travessa 14, 321, São Paulo, 05508-090, SP, Brasil.|Departamento De Biodiversidad Y Biología Experimental, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires & IBBEA, CONICET-UBA. Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
authors.forename: Renato Massaaki
authors.initials: RM
authors.lastname: Honji
authors.affiliation: Companhia Energética De São Paulo (CESP), Unidade De Hidrobiologia E Aquicultura, Rodovia Dos Tamoios, Km 38, 12260-000, Brasil.
authors.forename: Danilo
authors.initials: D
authors.lastname: Caneppele
authors.affiliation: Departamento De Biodiversidad Y Biología Experimental, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires & IBBEA, CONICET-UBA. Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
authors.forename: Matias
authors.initials: M
authors.lastname: Pandolfi
authors.affiliation: Departamento De Biodiversidad Y Biología Experimental, Facultad De Ciencias Exactas Y Naturales, Universidad De Buenos Aires & IBBEA, CONICET-UBA. Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
authors.forename: Fabiana Laura Lo
authors.initials: FL
authors.lastname: Nostro
authors.affiliation: Departamento De Fisiologia, Instituto De Biociências, Universidade De São Paulo, Rua Do Matão, Travessa 14, 321, São Paulo, 05508-090, SP, Brasil.
authors.forename: Renata Guimarães
authors.initials: RG
authors.lastname: Moreira
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002397:Catfishes / Q000145:classification / Q000196:embryology / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D056727:Endangered Species; D005260:Female; D029941:Fish Proteins / Q000378:metabolism*; D006062:Gonadotropins / Q000378:metabolism*; D013006:Growth Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D009865:Oocytes / Q000378:metabolism; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D012098:Reproduction; D014818:Vitellogenesis
chemical_list: D029941:Fish Proteins; D006062:Gonadotropins; D013006:Growth Hormone
keywords: follicle stimulating hormone; growth hormone; luteinizing hormone; prolactin hormone; reproductive dysfunction; somatolactin hormone