Endocrine disruption of phenanthrene in the protogynous dusky grouper Epinephelus marginatus (Serranidae: Perciformes)

FRIAS DE CAMPOS, MARIANA ; LO NOSTRO, FABIANA L.; DA CUÑA, RODRIGO H.; GUIMARÃES MOREIRA R.,

GENERAL AND COMPARATIVE ENDOCRINOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2018

0016-6480

The dusky grouper Epinephelus marginatus is a protogynous hermaphrodite fish, that maintains highlevels of plasma steroids as juveniles, as substrates for sex inversion. These fish are exposed to marinepollution from oil spills during cargo handling. Polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene(Phe), are the main crude oil components and are toxic to fish, acting as endocrine disruptors (ED).This is the first study that investigated impacts of Phe as an ED in E. marginatus juveniles. An in vivo sublethalexposure (96 h) to Phe was carried out at two concentrations (0.1 mg/L and 1 mg/L); exposure tothe vehicle (ethanol; ETOH) was also performed. Plasma levels of 17b-estradiol (E2), testosterone (T) and11-ketotestosterone (11-KT) were measured by ELISA. Gonads, liver and spleen were processed for histologicalanalysis. In an in vitro bioassay, gonad fragments were incubated with Phe (8.91 mg/L) orETOH. Steroid levels in the culture media were measured by ELISA. The in vivo exposure to Phe triggeredan increase of the area of the hepatocytes, increased number of melanomacrophagic centers andhemosiderosis in the spleen; ETOH induced similar effects on spleen. E2 and T levels did not change inplasma or in vitro media. In plasma, ETOH decreased 11-KT levels. Phenanthrene sharply reduced 11-KT levels in vitro. Although in vivo bioassay results were not unequivocal owing to ethanol effects, Phemight disrupt steroidogenesis in juvenile grouper, possibly causing dysfunctions during sex changeand gonadal maturity, considering the importance of 11-KT in developing ovaries.