Sandro Estevan Moron

Oxidative stress biomarkers and aggressive behavior in fish exposed to aquatic cadmium contamination

for 15 days (12isolated fish for each group) and afterward a behavioral test was performed. Fish from the control and cadmium-exposedgroups were paired for 1 h (6 pairs of fish per group) for determination of aggressiveness parameters. Immediately after thebehavioral test, the animals were sacrificed and the liver was used to determine biochemical parameters. Cadmium decreasedaggression in Nile tilapia. Subordinate animals exposed to cadmium showed decreased glutathione peroxidase (GSH-Px)activity compared to dominant ones. No alterations were observed in selenium-dependent glutathione peroxidase Se-GSH-Pand Cu-Zn superoxide dismutase activities, but total superoxide dismutase activity was increased in subordinate animalsexposed to cadmium compared to subordinate control. Catalase activity was increased in cadmium-exposed fish. Lipoperoxideconcentrations also increased in cadmium exposed fish indicating that cadmium toxicity may affect oxidative stress biomarkersin Nile tilapia. Social stress induced lipoperoxidation in Nile tilapia, and subordinate animals exposed to cadmium respondedwith lower activities of liver antioxidant enzymes compared to dominant fish. The present study shows that cadmium exposureis capable of inducing changes in the social status and oxidative stress parameters in this species.O objetivo deste estudo foi investigar a possivel relacao entre a exposicao ao cadmio, os marcadores hepaticos de estresseoxidativo e o comportamento agressivo em tilapia do Nilo (

Response of mucous cells of the gills of traíra (Hoplias malabaricus) and jeju (Hoplerythrinus unitaeniatus) (Teleostei: Erythrinidae) to hypo- and hyper-osmotic ion stress

As celulas mucosas (CM) em traira, Hoplias malabaricus, e jeju, Hoplerythrinus unitaeniatus, dois eritrinideos ecologicamente distintos, foram analisadas em especimes expostos a agua deionizada (DW) e agua com alta concentracao de ions (NaCl + Ca2+, HIW) durante 15 dias para avaliar as respostas das CMs. As CMs estao localizadas no lado aferente e eferente e regiao interlamelar no epitelio do filamento branquial, mas em H. unitaeniatus, CMs estao presentes no epitelio respiratorio ou lamelar. A densidade de CMs e menor em H. malabaricus, especie com respiracao exclusivamente aquatica, do que em H. unitaeniatus, especie com respiracao aerea facultativa. A transferencia para AD e HIW nao alterou a densidade de CMs e a sua superficie, exceto em H. malabaricus, no primeiro dia de exposicao a AD. Um unico tipo de CM contendo tres tipos de glicoproteinas (neutra, acida e acida sulfatada) foi identificado no epitelio branquial de H. malabaricus e H. unitaeniatus. A quantidade das glicoproteinas (avaliada pela intensidade da reacao histoquimica) diferiu nas duas especies e foi alterada apos a transferencia para AD e HIW mostrando pequeno ajuste na quantidade de cada mucosubstância secretada pelas CMs em H. malabaricus e reducao de glicoproteinas acidas e sulfatadas em H. unitaeniatus. A diminuicao dessas glicoproteinas em H. unitaeniatus reduz a protecao do muco sobre o tecido branquial quando e alterada a concentracao de ions na da agua.

Anatomopatologia de amostras de bovinos alimentados com glicerol

The increase in biodiesel production has led to higher production of crude glycerin, thus, numerous studies have highlighted the use of crude glycerin and glycerol as energy source to be used for animal feed production. However, its use has been closely watched because of the presence of contaminants such as methanol used in the process of separating fatty acids from glycerol. Methanol is an alcohol and has been responsible for intoxication in humans and primates, characterized by metabolic acidosis and eye problems, with less toxicity to other species. The toxic effects of methanol poisoning are attributed mainly to formic acid, a metabolite of the degradation process of methanol in the liver. The objective of this study was to verify the possible toxic action of crude glycerin and methanol by pathological examinations of the central nervous system (CNS), liver, rumen, small intestine and kidney from 24 feedlot cattle for 84 days, feed containing up to 24% of crude glycerin in dry matter (DM) presenting in its composition 80.35% glycerol, and <0.01% methanol. There were no pathological changes observed in dairy cows and steers up to 24% of glycerol inclusion based on the diet DM. The total weight gain and feed conversion were not affected by inclusion of glycerol. We conclude that crude glycerin can be included up to 24% of total DM in the diets of steers and dairy cows without compromising animal performance or display toxicity.

Use of biomarkers to evaluate the ecological risk of xenobiotics associated with agriculture

This research aimed to evaluate the ecological risk of xenobiotics associated with agricultural activities by determining metal contents and biomarker responses using tucunaré (Cichla sp.) as a bioindicator. The work was conducted in the southwest region of the state of Tocantins, in the cities of Lagoa da Confusão and Pium. Water samples and specimens of Cichla sp. were collected in the Javaés and Formoso Rivers at three collection points (A, B and C). The concentrations of Cd, Pb, Cu, Cr, Mn, Ni and Zn in water and fish were analyzed. In fish, genotoxic, biochemical (glucose serum levels, AST (aspartate aminotransferase) and ALT (alanine aminotransferase) and histological (gills and liver) biomarkers were assessed. In the water, the Cr and Mn concentrations at the three collection points exceeded the values for Class 1 rivers. In the muscle, Cr was above the maximum limit allowed for human consumption at the three collection points, although the values at Points B and C were not significantly different from that at Point A (p > 0.05). At the three collection points, the micronucleus test revealed a low frequency of micronuclei. Significant hyperglycemia and a decrease in the AST activity of the fish collected at Point C was observed. In the gills, the most frequent alterations were at Stages I and II, which indicated mild to moderate damage, and epithelial detachment was the most frequent variation. In the liver tissue, the most frequently observed histological changes were at Stages I and II and included cytoplasmic vacuolization, nuclear hypertrophy, dilated sinusoids and bile stagnation. The integrated evaluation of these biomarkers indicated that fish collected from areas with intense agricultural activities presented adaptive responses that were likely caused by the availability and bioaccumulation of certain xenobiotics in the environment.