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The effects of cypermethrin-based insecticide (CBI), commonly used in aquaculture and agriculture, were evaluated in matrinxa (Brycon amazonicus) exposed to sub-lethal concentration (20% of LC50) for 96 h. Physiological and biochemical effects were studied through biomarkers: lipid peroxidation (LPO), glutathione (GSH), and ascorbic acid concentrations; superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glucose-6-phosphate dehydrogenase (G6PDH) assays in the liver and gills. Besides, ions Na, Cl, and K; protein and glucose concentrations were measured in the plasma. Red blood cells count (RBC), hemoglobin concentration (Hb), hematocrit (Ht), and hematimetric parameters were evaluated in the total blood. The NKA (Na /K+ ATPase) activity was assayed in the gills. The histopathological effects of CBI were also investigated in the gills. The liver and gill LPO increased 62 and 100%, respectively. The tripeptide GSH concentration reduced in the liver and increased in the gill of exposed fish. The SOD and CAT activities increased in the liver, whereas CAT reduced in the gill. Liver also presented an increase in G6PDH activity. Plasma Na and Cl and glucose concentrations increased in the exposed fish. Levels of Ht, Hb and RBC were significantly increased. The gill NKA activity also increased. Exposed fish exhibited histological alterations in the gills such as hypertrophy and proliferation of chloride cells, blood vessels dilation, aneurysms and hemorrhage of the lamella. The histological index indicated moderate to heavy damage to the gills. CBI provokes liver and gills oxidative stress, gill structural damages, and ionic imbalance. A multi-biomarker approach allows us to see that B. amazonicus was unable to cope with CBI exposure.

Pyrethroids are insecticides widely used in agriculture to control ectoparasites and biological vectors. They can reach the water bodies by leaching and or runoff. Fishes are highly sensitive to pyrethroids and the nervous system sensibility and the deficient drug metabolism are the clues but the toxicity mechanisms are yet unclear. The acute toxicity assays allow evaluating the potential, environmental risks of specific pesticides. Type II pyrethroids are becoming widely used and there is no law concerning the limits of use to this kind of pesticide in Brazil. The LC 50 ;96h was evaluated for three pyrethroid basedinsecticides (PBI): cypermethrin, deltamethrin and λ-cyhalothrin in fish Brycon amazonicus. The LC 50 ;96h for the cypermethrin based-insecticide (CBI) was 36 µg L -1 ; for deltamethrin based-insecticide (DBI) was 2.6 µg L -1 ; and for λ-cyhalothrin (LBI) was 6.5 µg L -1 . During the tests some behavioral alterations were registered just after the exposure; they were more evident at the highest xenobiotics concentrations. These alterations were indicative of asphyxia and nervous system damages. The three insecticides are highly toxics to B. amazonicus and the degree of toxicity is: deltamethrin> λ-cyhalothrin> cypermethrin. The behavioral alterations observed are worrying since long-term exposure to sublethal concentrations can affect survival and reproductive ratios.

The present article tried to establish dark/light preference in five different species of teleosts. We proposed, using the data obtained with this method in zebrafishes (Danio rerio), Cardinal-tetras (Paracheirodon axelrodi), lambaris (Astyanax altiparanae), Nile tilapias (Oreochromis niloticus), guppies (Poecilia reticulata) and banded-knife fishes (Gymnotus carapo), that preference for dark environments is a reliable and low-cost index of anxiety/fear in those species. A scototactic pattern of exploration was found in all species, and the pattern of locomotion in the white environment suggests its aversiveness for those species, with the exception of G. carapo and O. niloticus. A comparative analysis uncovered species differences in approach-avoidance dimensions of the task. The data are discussed in terms of the behavioral ecology of the animals and prey-predator relationships, suggesting a link with predator defense strategies in teleost.The dark/light preference model is already established as an "ethoexperimental" anxiety model in rodents (cf. Bourin & Hascöet, 2003). It is based on the natural aversive quality of brightly-lit environments for mice, shaping -352 -a conflict situation in which the animal must deal with its natural tendency to explore in face of the aversiveness of the environment. The rodent dark/light preference model is an exploration model, in the sense that it measures locomotor activity in both environments as an index of anxiety (Green & Hodges 1991; Prut & Belzung 2001; Belzung & Griebel 2003; Hascöet, Bourin, & Dhonnchadha, 2001); there are other, non-locomotor, models of anxiety (eg., inhibitory avoidance), but those are not of concern for the objectives in this article. Locomotor models of anxiety use exploratory behavior (defined as "a speciesspecific behaviour pattern concerned with the gathering of information" concerning the environment: O' Keefe & Nadel, 1978, p. 242) as an index of anxiety or anxiety-like states, relating it to foraging behavior or to appraisal of novel environmental stimuli (Belzung & Griebel 2001;File, 2001). The main rationale is that exploratory behavior would correlate with neophobia, a tendency to avoid new environments (Misslin & Cigrang 1986), forming a mixed pattern of behavior that consists in gradual approaching and exploration of the new environment associated with "scanning" and "risk-assessment" behaviors.Ethoexperimental models use variables that are akin to the concept of "antipredator apprehension" from behavioral ecology (risk assessment, defensive distance, predatory imminence continuum, risk associated suppression of competing motivational systems; Kavaliers & Choleris, 2001). Apprehension is considered to reflect a motivational state, and is defined as "any reduction in attention to other activities (e. g., foraging, mate seeking) as a result of increasing the allocation of attention to detecting and/or responding to potential predators" (Kavaliers & Choleris, 2001, p. 579). Exploratory apprehensive behavior (denoting the pattern of ex...

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Phenol is an aromatic chemical commonly found in domestic and industrial effluents that represents a worldwide concern in toxicology. When it reaches aquatic environments, significant damage in fishes is observed. The first aim of this study was to investigate the acute toxicity levels of phenol in Ictalurus punctatus and Piaractus mesopotamicus. The second objective was to evaluate the hematological parameters of I. punctatus and P. mesopotamicus after 96 hours exposure to sublethal concentration of phenol (10% of 96-hour LC 50) and after post-exposure recovery period of 7 days. The main hypothesis of the study was that even sublethal phenol concentration could cause hematological alterations in fish. For 96-hour LC 50 tests, both fish species were exposed to several phenol concentrations (in the range between 5 and 50 mg L-1) and the mortality were recorded after 24, 48, 72 and 96 hours. Phenol was notably more toxic to I. punctatus than P. mesopotamicus and the 96-hour LC 50 values were 15.08 and 32.56 mg L-1 , respectively. Sublethal exposure to phenol in P. mesopotamicus resulted in significant higher hematocrit level (Ht), hemoglobin content (Hb) and red blood cell count (RBC) in comparison with control group. In I. punctatus, Ht, Hb and RBC remained constant after 96-hour sublethal exposure. However, after the recovery period of 7 days a significant increase of RBC followed by reduction in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were observed in I. punctatus. The sublethal responses to phenol revealed erythropoeisis in I. punctatus and respiratory distress in P. mesopotamicus. P. mesopotamicus presented excessive skin and gills mucus throughout the 96-hour LC 50 tests. Acute toxicity tests and hematological responses after exposure to sublethal phenol concentration could be successfully used as a biomarker of stress in fish and may be applicable to investigate others toxic agents.

The purpose of the present study was to evaluate the effects of the resistance training (RT) on the lipid profile and metabolism, oxidative stress, and activity of metalloproteinase-2 (MMP-2) in the left ventricle (LV) of dietinduced obesity rats. Methods: Forty males Wistar rats 90 days-old were grouped into four groups (n=10): i) Sedentary group (SED); ii) Obese sedentary group, feed with high-fat diet (Ob-SED); iii) Resistance Trained group (RT), and iv) Obese Resistance trained group (Ob-RT). The LV was assayed to Obesity index, LV lipid content, citrate synthase activity, lipid peroxidation (TBARS), enzymatic and non-enzymatic antioxidant systems, lipid profile, cardio-metabolic parameters, and activity of MMP-2. Results: High-fat diet was associated with manifestations of the obesity, body mass gain, and increased obesity index, accompanied by an alteration in the lipid profile. On the other hand, RT was able to prevent body weight gain, to reduce the obesity index and to improve the lipid profile, to elevate the activation of the citrate synthase, and to decrease MMP-2 activity in the LV of obese rats. Conclusion: RT positively modulated blood lipid profile and antioxidant enzymes preventing the increased activity of MMP-2 in the left ventricle from rats fed with high-fat diet.

Metabolic adjustments were studied in channel catfi sh Ictalurus punctatus exposed to 1.5 mg L -1 of phenol (10% LC50) for four days and recovered for seven days. Lower triacylglycerol (TGA) stores and increased muscle fat free acids (FFA) suggest fat catabolism in muscle. Remarkable liver FFA decrease (-31%) suggests liver fat catabolism as well. Increased muscular ammonia levels and ASAT (aspartate aminotransferase) and decreased plasma aminoacids suggest higher muscular amino acid uptake. Constant levels of glucose and increased liver glycogen stores, associated with lower amino acids in plasma, indicate gluconeogenesis from amino acids. This is supported by higher hepatic ALAT and ASAT. Higher hepatic LDH followed by lower plasma lactate may indicate that plasma lactate was also used as gluconeogenic substrate. Biochemical alterations were exacerbated during the post-exposure recovery period. Reduction in muscle and plasma protein content indicate proteolysis. A higher rate of liver fat catabolism was resulted from a remarkable decrease in hepatic TGA (-58%). Catabolic preference for lipids was observed in order to supply such elevated energy demand. This study is the fi rst insight about the metabolic profi le of I. punctatus to cope with phenol plus its ability to recover, bringing attention to the biological consequences of environmental contamination.