title: Kiss2 as a Regulator of Lh and Fsh Secretion via Paracrine/Autocrine Signaling in the Teleost Fish European Sea Bass (Dicentrarchus labrax).
abstract: Kisspeptins are key players in the neuroendocrine control of puberty and other reproductive processes in mammals. Several studies have demonstrated that the KISS/GPR54 system is expressed by gonadotrophs, but in vitro studies assessing the direct stimulatory effects of kisspeptin on gonadotropin secretion in the pituitary have provided conflicting results. In this study, we investigated whether kisspeptin directly influences the reproductive function of sea bass pituitary. First, the highly active peptides Kiss1-15 and Kiss2-12 were used to stimulate dispersed sea bass pituitary cells obtained from mature males. Our results show that, first, Kiss2-12 induced luteinizing hormone (Lh) and follicle-stimulating hormone (Fsh) release, whereas Kiss1-15 had no effect on gonadotropin secretion at full spermiation stage. Second, the distribution and nature of Kiss2 and its potential interactions with the gonadotropin-releasing hormone 1 (Gnrh1) system in the pituitary were analyzed using dual fluorescence immunohistochemistry. Kiss2 cells were found in the proximal pars distalis and colocalized with gonadotropin-immunoreactive cells. In summary, our results provide, for the first time in a teleost species, functional and neuroanatomical evidence that Kiss2 may act through different routes to directly modulate the activity of gonadotrophs, either as a hypophysiotropic neuropeptide or as an autocrine/paracrine factor.
authors.affiliation: Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre la Sal (IATS), Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Espigares
authors.affiliation: Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre la Sal (IATS), Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Zanuy
authors.affiliation: Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre la Sal (IATS), Consejo Superior de Investigaciones Científicas (CSIC), Castellón, Spain a.gomez@csic.es.
authors.forename: Ana
authors.initials: A
authors.lastname: Gómez
mesh_terms: D000818:Animals; D019898:Autocrine Communication; D001492:Bass / Q000378:metabolism*; D002478:Cells, Cultured; D005640:Follicle Stimulating Hormone / Q000096:biosynthesis / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives; D059648:Kisspeptins / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000096:biosynthesis / Q000378:metabolism*; D008297:Male; D019899:Paracrine Communication; D010902:Pituitary Gland / Q000378:metabolism*
chemical_list: D059648:Kisspeptins; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
keywords: follicle-stimulating hormone; gonadotropins; kisspeptin; luteinizing hormone; pituitary cell culture; reproduction