Characterization of gonadotropin inhibitory hormone in Cichlasoma dimerus

MARÍA PAULA DI YORIO; DANIELA PEREZ-SIRKIN; TOMAS H. DELGADIN; KAZUYOSHI TSUTSUI; GUSTAVO M. SOMOZA; PAULA VISSIO

Chascomus

Congreso; XVI Jornadas Anuales de la Sociedad Argentina de Biología; 2014

Sociedad Argentina de Biología

GnIH is a novel hypothalamic RFamide neuropeptide capable of inhibiting the release of gonadotropins in birds and mammals. The aim of this work was to characterize its preprohormone sequence, tissue distribution and effect over pituitary hormones. We identified cdGnIH precursor showing 3 putative LPXRFamide peptides. Analyzing the tissue distribution of GnIH mRNA in the reproductive axis we detected a high expression in hypothalamus and testes. By immunohistochemistry we observed GnIH somas in the nucleus posterioris periventricularis and a great number of ir-fibers widespread in all the brain regions. Finally, we performed in vitro studies with synthetic cdGnIH-2 and -3 to evaluate their effects on GH, LH and FSH. Preliminary results indicate a biological effect of cdGnIH-2 on pituitaries hormone release. In conclusion, GnIH was identified in C. dimerus and judging the distribution pattern and in vitro results, GnIH could be involved in the regulation of reproductive function.