ATYPICAL ARRANGEMENT AND DISTRIBUTION OF KISSPEPTIN, NEUROKININ B AND DYNORPHIN A IN

ALEJANDRO RAÚL SCHMIDT, PABLO IGNACIO FELIPE INSERRA, SANTIAGO ELÍAS CHARIF, SANTIAGO ANDRES CORTASA, SOFÍA PROIETTO, MARÍA CLARA CORSO; HALPERIN J; ALFREDO DANIEL VITULLO; DORFMAN, VERÓNICA BERTA

Ciudad Autonoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIC, SAIB, SAA, SAI, SAB, SAB, SAFE, SAFIS, SAH y SAP

Considering that KNDy (kisspeptin, neurokinin B and DynorphinA) cells are localized in the arcuate nucleus (ARC) of mostmammals and modulate gonadotropin-releasing hormone (GnRH)expression and secretion, the aim of this work was to identify thepresence of the KNDy cells in the hypothalamus of South Americanplains vizcacha (Lagostomus maximus) and its relation with GnRHand hormone receptors involved in reproduction. Adult non-pregnantfemale vizcachas were captured in the Estación de Cría de AnimalesSilvestres (ECAS) during March (n=7). Its brains were removed andfixed. Kluwer-Barrera staining was performed to determine ARCand anteroventral periventricular hypothalamic nucleus (AVPV) localization.To study KNDy cells arrangement, immunofluorescencefollowed by paired confocal microscopy was developed. NeurokininB(NKB), dynorphin-A (DYN), kisspeptin (Kiss), Kiss receptor(GPR54), GnRH, estrogen receptor alpha (ERα) and progesteronereceptor (PR) were labelled. A few number of NKB/Dyn immunoreactiveneurons, somas and fibers, were found in ARC. Surprisingly,NKB+/Dyn+ neurons were more abundant in AVPV than in ARC.However, Kiss was not detected in NKB+/Dyn+ neurons of both ARCand AVPV but were individually found in somas of AVPV and in fibersof ARC. In addition, GPR54 colocalized with GnRH in neurons ofAVPV. Both Kiss+ and NKB+/Dyn+ cells showed colocalization of ERαand PR. This is the first description of the KNDy components distributionin the hypothalamus of the vizcacha. An atypical arrengementof KNDy system was detected in AVPV. The expression of NKB/Dynand Kiss in separate neurons and the lack of Kiss immunoreactivesomas in ARC, suggest a singular model of KNDy system in thevizcacha with physical separation but possibly with a coordinatedfunction. This results may indicate that GnRH neurons could be directlyregulated by the hormonal environment via ERα and PR, andindirectly by Kiss and NKB/Dyn in Lagostomus maximus.