&lt;b&gt;Induced CYP1A activity and DNA damage in fish from the middle Paraíba do Sul River basin, southeastern Brazil

Claudio Nona Morado,Francisco Gerson Araujo,Francisco José Roma Paumgarten,Thiago Estevan Parente Martins,Iracema David Gomes

doi:10.4025/actascibiolsci.v40i1.36666

<b>Induced CYP1A activity and DNA damage in fish from the middle Paraíba do Sul River basin, southeastern Brazil

Claudio Nona Morado, Francisco Gerson Araujo + Show 3 more

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https://doi.org/10.4025/actascibiolsci.v40i1.36666

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Abstract

The Paraiba do Sul River (PSR) drainage basin in Southeastern Brazil covers one of the most industrialized and densely populated regions of the country. The impact of chemical contamination on the PSR basin seems to be more pronounced in its middle reach where a number of potentially polluting plants are located. In this study, we used hepatic EROD activity - a biomarker of exposure to CYP1A-inducing pollutants (e.g. PAHs, PCDD/Fs, PCBs) - and the incidence of micronucleated erythrocytes (Mn) in the peripheral blood - a biomarker of effects of DNA-damaging agents (e.g. PAHs) - to evaluate the effects of pollution on two native fish species, Geophagus brasiliensis and Pimelodus maculatus . Results showed that the incidence of Mn and EROD in G. brasiliensis and P. maculatus from the two most downstream sites (Tres Rios Town and Piabanha River) were markedly higher than the incidence of Mn and EROD recorded in fish from the most upstream site (Funil Reservoir). Our findings are consistent with the view that CYP1A-inducing activity and increased DNA-damage are found in fish caught in sampling sites located downstream of the stretch where there are several industries that are potential sources of PAHs and CYP1A-inducing contaminants.

Highlights

The Paraíba do Sul River (PSR) is one of the longest and most important rivers of Southeastern Brazil
Livers from yellow mandi and blood smears from acará fish caught in site 5 were lost and the respective EROD and micronucleated erythrocytes (Mn) incidence values are missing in Table 2 and 3
The clearly induced CYP1A-mediated activities in fish (G. brasiliensis and P. maculatus) from the two most downstream sampling sites evaluated in this study suggested that the middle reach of the PSR basin is contaminated with polycyclic aromatic hydrocarbons (PAHs) and/or with other Aryl Hydrocarbon Receptor (AhR) ligands (PCBs, Polychlorinated Dibenzofurans (PCDD/Fs))

Summary

Introduction

The Paraíba do Sul River (PSR) is one of the longest and most important rivers of Southeastern Brazil. It rises in the Sea Mountain range in the State of São Paulo and flows 1,140 km before meeting the Atlantic Ocean on the Northern Coast of the State of Rio de Janeiro (Figure 1). Since the PSR drainage basin covers over one of the most industrialized and densely populated regions of the country, it has suffered a strong impact from human activities. The PSR basin is a major source of potable water supply for Greater Rio de Janeiro City and for a number of other smaller cities, and two hydropower plant reservoirs are located in the middle reach of the river The pollution of PSR waters by industrial effluents and untreated domestic sewage, has been cause for deep concern during the last decades (Nascimento, Araújo, Gomes, Mendes, & Sales, 2012; Santos, Albieri, & Araújo, 2013)

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