Exposure to E2 and EE2 environmental concentrations affect different components of the Brain-Pituitary-Gonadal axis in pejerrey fish (Odontesthes bonariensis)

GARRIZ A; DEL FRESNO P; MIRANDA LA

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2017 vol. 144 p. 45 - 53

0147-6513

The present study focuses on the effects of E2 and EE2environmental concentrations on different components of the reproductive axisof pejerrey (Odontesthes bonariensis),a native fish species from Pampas lakesof Argentina. The results obtained demonstratedthat E2 and EE2 separate or mixed, could disrupt key pathwaysof the pejerrey Brain-Pituitary-Gonadal axis. First, it was observed that at thebrain level, gnrh-III and cyp19a1b mRNA expression increased significantly in the exposed fish. Secondly, inthe pituitary fshb and lhb mRNA expression levels, the study didnot show any differences between treated and control groups. Thirdly, fshr and lhcgr transcript levels showed a significant decrease attesticular level. Nevertheless, testosteroneplasmatic levels remained unchanged in exposed fish. In addition, in a histologicalanalysis, it was possible to find pyknotic nuclei in estrogen only on treatedfish testis linked to a reduction in the GSI index and a decrease in the lengthof spermatogenic lobules. All these findings highlighted the fact that environmentalconcentrations of E2, EE2 and their mixture disrupted theendocrine-reproductive axis of pejerrey, being the testis the main directtarget.