Fish exposure to nano-TiO2 under different experimental conditions: Methodological aspects for nanoecotoxicology investigations

The ecotoxicology of nano-TiO2 has been extensively studied in recent years; however, few toxicological investigations have considered the photocatalytic properties of the substance, which can increase its toxicity to aquatic biota. The aim of this work was to evaluate the effects on fish exposed to different nano-TiO2 concentrations and illumination conditions. The interaction of these variables was investigated by observing the survival of the organisms, together with biomarkers of biochemical and genetic alterations. Fish (Piaractus mesopotamicus) were exposed for 96h to 0, 1, 10, and 100mg/L of nano-TiO2, under visible light, and visible light with ultraviolet (UV) light (22.47J/cm2/h). The following biomarkers of oxidative stress were monitored in the liver: concentrations of lipid hydroperoxide and carbonylated protein, and specific activities of superoxide dismutase, catalase, and glutathione S-transferase. Other biomarkers of physiological function were also studied: the specific activities of acid phosphatase and Na,K-ATPase were analyzed in the liver and brain, respectively, and the concentration of metallothionein was measured in the gills. In addition, micronucleus and comet assays were performed with blood as genotoxic biomarkers. Nano-TiO2 caused no mortality under any of the conditions tested, but induced sublethal effects that were influenced by illumination condition. Under both illumination conditions tested, exposure to 100mg/L showed an inhibition of acid phosphatase activity. Under visible light, there was an increase in metallothionein level in fish exposed to 1mg/L of nano-TiO2. Under UV light, protein carbonylation was reduced in groups exposed to 1 and 10mg/L, while nucleus alterations in erythrocytes were higher in fish exposed to 10mg/L. As well as improving the understanding of nano-TiO2 toxicity, the findings demonstrated the importance of considering the experimental conditions in nanoecotoxicological tests. This work provides information for the development of protocols to study substances whose toxicity is affected by illumination conditions. © 2013 Elsevier B.V..

Pollution-induced metabolic responses in hypoxia-tolerant freshwater turtles

The physiological control to support the absence of O2 for long periods of diving, and oxidative damage impact caused by the whole process of hypoxia/reperfusion in freshwater turtles is well known. However, effects of contaminants may act as co-varying stressors and cause biological damage, disrupting the hypoxia/reperfusion oxidative damage control. In order to investigate the action of environmental stressors present in domestic or industrial wastewater effluent, we performed a biochemical analysis of biotransformation enzymes, oxidative stress, as well as neuromuscular, physiological and morphological parameters in Phrynops geoffroanus, an hypoxic-tolerant freshwater turtle endemic of South America, using animals sampled in urban area, contaminated by sewage and industrial effluents and animals sampled in control area. Here we demonstrate the physiological and biochemical impact caused by pollution, and the effect that these changes cause in antioxidant activity. Animals from the urban area exhibited higher EROD (ethoxyresorufin-O-deethylase, CYP1A1), GST (glutathione S-transferase), G6PDH (glucose-6-phosphate deshydrogenase), AChE (acetilcholinesterase) activities and also TEAC (trolox-equivalent antioxidant capacity) and TBARS (thiobarbituric acid reactive substances) values. We examined whether two morphometric indices (K - condition factor and HIS - hepatosomatic index) which help in assessing the general condition and possible liver disease, respectively, were modified. The K of the urban animals was significantly decreased compared to the control animals, but the HIS value was increased in animals from the urban area, supporting the idea of an impact in physiology and life quality in the urban freshwater turtles. We propose that this freshwater turtle specie have the ability to enhance its antioxidants defenses in order to protect from tissue damage caused by hypoxia and reperfusion, but also that caused by environmental contamination and that the oxidative damage control in hypoxic conditions has resulted in an adaptive condition in hypoxic-tolerant freshwater turtle species, in order to better tolerate the release of contaminated effluents resulting from human activity. © 2013 Elsevier Inc.

Estudo de variações bioquímicas e morfológicas induzidas por peticidas orgnofosforado e carbamato em tilápia (oreochromis niloticus) e cascudo (Pterygoplichthys anisitsi), como biomarcadores de contamincação ambiental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de biomarcadores de contaminação em tilápias do nilo (oreochromis niloticus) expostas aos herbicidas combine *500sc (tebutiurom) e velpar k® wg (diurom + hexazinona)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de biomarcadores bioquímicos em cascudos (Pterygoplichthys anisitsi) expostos a óleo diesel e biodiesel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo comparativo do estresse oxidativo entre tilápias (Oreochromis niloticus) e cascudos (Pterygoplichthys anisitsi) expostos a óleo diesel e a biodiesel

Pós-graduação em Biologia Animal - IBILCE

Efeitos do treinamento aeróbio na hepatocarcinogênese química em ratos Wistar alimentados com dieta basal ou hiperlipídica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho e estabilidade de parâmetros bioquímicos em materiais de controle líquidos congelados e sólidos liofilizados

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

Dieta hiperlipídica e exercício físico: conseqüências sobre o metabolismo e a peroxidação lipídica - estudo em modelo animal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Parâmetros hematológicos e bioquímicos séricos de jumentos (Equus asinus) da raça Pêga

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estabilidade de constituintes bioquímicos frente a diferentes temperaturas e períodos de estocagem, em amostras de soro de cães hígidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da prliferação e apoptose com a utilização de arranjos em matriz de amostra tecidual (Tissue Microarray - TMA) em mastocitomas cutâneos caninos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acompanhamento clínico-laboratorial de gatos naturalmente infectados com vírus da imunodeficiência (FIV) tratados com zidovudina(AZT)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do perfil hemostático, hematológico e bioquímico de cães com doença hepática

Pós-graduação em Medicina Veterinária - FMVZ

Avaliação da glutationa e suas enzimas como marcadores prognósticos e preditivos do câncer de mama

Pós-graduação em Genética - IBILCE