Gabriela Rodríguez Manzo - The endocrine disruptor DE-79 alters oxytocinergic transmission and sexual behavior expression in male rats

14 de Octubre de 2023

Invitamos a leer el artículo: “The endocrine disruptor DE-79 alters oxytocinergic transmission and sexual behavior expression in male rats”, en la que colaboró la Doctora Gabriela Rodríguez Manzo, Investigadora de Cinvestav Sede Sur

Autores: René Garduño Gutiérrez, Gabriela Rodríguez Manzo, Alejandro Velázquez Alvarado, Carolina Miller Pérez, Martha León Olea

Felicitamos al estudiantado y profesorado que contribuyeron en esta investigación por su arduo trabajo.

Abstract: Polybrominated diphenyl ethers (PBDEs), used as flame retardants are persistent organic pollutants exerting important health effects. PBDEs with >5 bromide substitutions were considered less harmful and therefore extensively used commercially. DE-79 was a widely used PBDE mixture of hexa-, hepta-, octa- and nona-brominated compounds that increases vasopressin (AVP) production. AVP and oxytocin (OT) are both produced in neurons of the supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei projecting to the neurohypophysis and to brain regions involved in copulatory behavior. OT plays an important role in male copulation. Since DE-79 alters AVP expression in the SON and PVN, it might also modify OT content and alter male sexual behavior. We analyzed if repeated DE-79 exposure of adult male rats affected OT content and OT receptor (OTR) density in the SON, PVN, medial preoptic area (mPOA), ventral tegmental area, nucleus accumbens, and amygdala, and if male copulatory behavior was affected. We show that DE-79 exposure produces a generalized decrease in brain OT immunoreactivity, increases OTR density in all brain regions analyzed but the mPOA, and reduces the ejaculatory threshold after a first ejaculation. The documented ejaculation-induced OT release might participate in this last effect. Thus, one-week DE-79 exposure alters the OT-OTR system and modifies male rat sexual performance. Based on the literature it could be speculated that these effects are related to the putative endocrine disrupting actions of DE-79, ultimately altering brain OT levels and OTR expression that might affect copulation and other important OT-mediated brain functions.

Keywords: Brain regions; Ejaculatory threshold; Endocrine disruptor; Oxytocin-oxytocin receptor system; PBDE; Rat male sexual behavior.