title: The involvement of gonadotropins and gonadal steroids in the ovulatory dysfunction of the potamodromous Salminus hilarii (Teleostei: Characidae) in captivity.
abstract: Potamodromous teleosts that require migration to reproduce show dysfunctions that block ovulation and spawning while in captivity. To understand the physiological basis of these reproductive dysfunctions, follicle-stimulating hormone b subunit (fshb) and luteinizing hormone b subunit (lhb) gene expression analyses by real-time quantitative PCR, together with measurements of estradiol (E 2), 17α-hydroxyprogesterone (17α-OHP) and 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DHP) levels, were carried out throughout the reproductive cycle of the potamodromous Salminus hilarii. The following reproductive stages were evaluated in captive and wild females: previtellogenic (PV), advanced maturation/mature (AM) and regression/spent (REG/SPENT). In the wild females, fshb expression decreased from the PV to the AM stage, and the opposite pattern was detected for E 2, which increased from the PV to the AM stage. fshb was expressed at lower levels in captive than in wild females, and this difference did not change during the reproductive cycle. lhb expression also increased from the PV to the AM stage in both groups, but the wild females at the AM and REG/SPENT stages showed higher lhb expression levels than the captive females. The concentrations of 17α-OHP did not change during the reproductive cycle, and the levels were higher in the captive than in the wild females at all reproductive stages. 17α,20β-DHP levels did not change between wild and captive females. However, in captive females, the transition from PV to AM stage was followed by an increase in 17α,20β-DHP levels. These data indicate that dysfunctions in the gonadotropins and steroids synthesis pathways cause the ovulation failure in captive S. hilarii.
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, no 321, São Paulo, SP, 05508-090, Brazil. renatagm@ib.usp.br.
authors.forename: Renata Guimarães
authors.initials: RG
authors.lastname: Moreira
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, no 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Renato Massaaki
authors.initials: RM
authors.lastname: Honji
authors.affiliation: Núcleo de Biotecnologia, Universidade de Mogi das Cruzes, Mogi das Cruzes, SP, Brazil.
authors.forename: Renato Garcia
authors.initials: RG
authors.lastname: Melo
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, no 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Amanda de Moraes
authors.initials: Ade M
authors.lastname: Narcizo
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, no 321, São Paulo, SP, 05508-090, Brazil.
authors.forename: Juliane Suzuki
authors.initials: JS
authors.lastname: Amaral
authors.affiliation: Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors.forename: Ronaldo de Carvalho
authors.initials: Rde C
authors.lastname: Araújo
authors.affiliation: Núcleo de Biotecnologia, Universidade de Mogi das Cruzes, Mogi das Cruzes, SP, Brazil.
authors.forename: Alexandre Wagner Silva
authors.initials: AW
authors.lastname: Hilsdorf
mesh_terms: D019326:17-alpha-Hydroxyprogesterone / Q000097:blood; D000818:Animals; D060126:Characidae / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000502:physiology; D012739:Gonadal Steroid Hormones / Q000502:physiology*; D006062:Gonadotropins / Q000502:physiology*; D006908:Hydroxyprogesterones / Q000097:blood; D007986:Luteinizing Hormone / Q000502:physiology; D010053:Ovary / Q000503:physiopathology*; D010060:Ovulation
chemical_list: D012739:Gonadal Steroid Hormones; D006062:Gonadotropins; D006908:Hydroxyprogesterones; C007433:17,20-dihydroxy-4-pregnen-3-one; D004958:Estradiol; D019326:17-alpha-Hydroxyprogesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
keywords: 17α,20β-Dihydroxy-4-pregnen-3-one; 17α-Hydroxyprogesterone; Estradiol; Gonadotropins; Reproductive dysfunction