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Examinando por Materia "EROD"

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    PublicaciónAcceso abierto
    Ecotoxicology of polycyclic aromatic hydrocarbons and petroleum wastewater in the orinoquia region
    (Society of Environmental Toxicology and Chemistry (SETAC) Latin America 15 Biennial Meeting, 2023-09-20) Calderón-Delgado, Ivonne; Velasco Santamaría, Yohana María; Corredor-Santamaría, Wilson
    Polycyclic aromatic hydrocarbons (PAH) are ubiquitous and characterized by low solubility, persistence in the environment, bioaccumulation in biota and high toxicity. Aquatic systems receive PAH through atmospheric deposition and direct runoff release, with the organisms that inhabit them being their main targets. Among these, fish are of particular interest because they occupy key positions in aquatic and terrestrial food webs. Petroleum extraction is one of the most relevant sectors in Colombia's economy; however, the environmental impact due to oil extraction and spillage accidents has generated contamination of soils and water sources, mortality of fauna and flora or changes in the dynamics of natural ecosystems, among others. Biomonitoring of oil pollution using aquatic organisms, especially native species has a great ecological relevance. In this sense, fish are considered as one of the main sentinel species to assess the state of aquatic ecosystems because they are ubiquitous in most aquatic environments exposed to contaminants and also because of their ecological relevance. Our data show alterations in fish from oil industry wastewater discharge sites and fish exposed to different PAH. In fact, concentrations of 250 and 70 ng/L of naphthalene (NAP) and phenanthrene (PHE), respectively, were recorded in rivers exposed to the discharge of produced water. Subacute exposures to sublethal concentrations of NAP 100 µg/g, PHE 50 µg/g and benzo[a]pyrene (BaP) 10 µg/g were evaluated. The results shown presence of genotoxicity in peripheral blood erythrocytes and nuclear abnormalities being higher in fish exposed to PHE, followed by BaP, and NAP, alteration in antioxidant response, fish exposed to BaP showed a significant increase in 7ethoxyresorufin-O-deethylase activity compared to the control, and presence of deleterious changes in tissue architecture such as hyperemia, degeneration of the nuclei, cytoplasmic degeneration, and vacuolization that could lead in the long term to a decline in fish populations exposed to these conditions. In conclusion, the results show that native Colombian fish such as Aequidens metae, Astyanax gr. bimaculatus and Piaractus orinoquencis are good sentinels of freshwaters potentially contaminated by hydrocarbons or in laboratory studies aimed at understanding the impact of petroleum compounds. Acknowledgment: This study was funded by Colciencias-ANH and Universidad de los Llanos Project number 112272151869, grant 721 – 2015.
  • Miniatura
    PublicaciónAcceso abierto
    Induction of cytochrome P4501A and biliary metabolites of pyrene and phenanthrene in Aequidens metae under laboratory conditions
    (Society of Environmental Toxicology and Chemistry (SETAC) Latin America 13 Biennial Meeting, 2018-09-18) Mora-Solarte, Diego Alejandro; Calderón-Delgado, Ivonne; Velasco Santamaría, Yohana María
    Oil toxicity is a subject of ongoing research and it is important to gain knowledge about baseline levels in order to evaluate the environmental risk assessments associate to oil pollution in aquatic environments and to determine possible adverse effects on aquatic organisms. The study of biomarkers is suggested as an appropriate strategy to study the sublethal effects of contaminants, providing an early indication of possible adverse effects on organisms. The aim of this study was to evaluated two biomarkers in a freshwater fish commonly known as luminosa (Aequidens metae) through acute exposure to pyrene and phenanthrene by intraperitoneal induction. The fish were exposed for 10 days to nominal concentrations of 1, 10 and 50 ppm of pyrene and phenanthrene. Fish were sampled three times during the exposure time. In each fish, liver and bile were collected and kept in -80 ºC until the analysis. The induction of cytochrome P450 in the liver was estimated by ethoxyresorufin-Odeethylase (EROD) activity and the determination of PAH metabolites in bile was measured. The hepatic EROD activity showed an increase and biliary metabolites of pyrene and phenanthrene showed decreasing levels after the first sampling time, indicating the biotransformation efficiency of PAHs. Fish exposed to the highest concentration of pyrene showed higher levels of pyrene metabolites in bile and higher CYP1A induction evidencing monotonic effect. These dose-response data can be used as useful contributions in assessing environmental risk with respect to effluent pollution from the oil industry in Colombia.