Endocrine Abstracts

The aim of the current study was to determine whether the porcine ovary was capable of metabolizing polybrominated diphenyl ether – BDE-47, which is the most abundant congener found in wildlife and in humans. It have been showed by us that this congener disrupt ovarian function by direct action on steroidogenesis. In the current study we analyzed the activity and expression of enzymes involved in phase I (CYP1A1 and CYP2B1/2) and phase II (SULT1A and COMT) of BDE-47 metabolism. CYP1A1 and CYP2B1/2 activity was determinated by conversion of ethoxy- and pentoxyresorufin in resorufin respectively, using fluorescent method. Enzymes of II phase of metabolism were evaluated by colorimetric methods: SULT1A activity was based on sulfotransferase ability to release p-nitrophenol with the PAPS, and the activity of COMT, based on the ability of catechol-O-methyltransferase to convert nitrocatechol (NC) for 3-metylnitrocatechol (2-methoxy-4-nitrophenol) with S-adenosylmethionine (SAM). Additionally, protein level was determined by immunoblot and ELISA.

Basal CYP1A1 and CYP2B1/2 activity increased during culture. BDE-47 had no effect on CYP1A1 activity, however CYP2B1/2 activity increased after exposure for 1 and 6 h. Basal SULT1A activity was 2.5 fold lower than that of COMT, and both proteins were stable during culture. BDE-47 increased SULT1A activity after exposure for 6 and 12 h, and COMT activity increased after exposure for 24 and 48 h. For the first time we demonstrated SULT1A protein levels in pig ovary measured by immunoblot and ELISA analyses. BDE-47 had no effect on the expression of all investigated enzymes.

In conclusion, fast activation of CYP2B1/2 and late activation of COMT (with a very low basal SULT1A activity) indicates a possible action of locally produced hydroxylated metabolites prior to their detoxification.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.