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1.
Artigo em Inglês | MEDLINE | ID: mdl-30759364

RESUMO

This study aims to evaluate the contamination of the water of Lagoa Tramandaí on Genidens genidens and Citharichthys spilopterus residents of Lagoa Tramandaí, a region susceptible to environmental damage due to the release of domestic sewage from the municipalities bathed by the lagoon. Thereby, the biota suffers the interference of heavy metals, affecting their behavior and the metabolism of these individuals. The hepatic and muscular glycogen, glucose and plasma lactate of these species were analyzed, as well as the presence of heavy metals in lagoon water. When the species were analyzed separately with their controls, both mobilized more glycogen than the control and presented increased glucose and lactate, which is characteristic of animals contaminated by heavy metals. When compared with each other, they showed differences regarding carbohydrate metabolism. It was observed that the Guri Sea Catfish suffers more influence of heavy metals than the Bay whiff. Thus, we can conclude that the water contaminated with heavy metals of this lagoon interferes in the carbohydrate metabolism of both species of fish.


Assuntos
Metabolismo dos Carboidratos/efeitos dos fármacos , Peixes-Gato , Linguados , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brasil
2.
PeerJ ; 6: e5343, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30090692

RESUMO

Here we show that the feeding regimen modulates zebrafish (Danio rerio) behavior. With regard to the time elapsed between feeding and behavioral evaluation, fish fed 3 h before behavioral evaluation in the novel tank test (NTT) showed decreased activity and a trend toward an anxiolytic reaction (increased use of the upper section of the aquarium) in comparison to fish fed 0.5, 6, 12, 24 or 48 h before testing, although differences were not statistically significant for all comparisons. Activity and use of the upper section of the aquarium did not differ significantly among the other treatments. Regarding feeding frequency, fish fed once a day showed higher anxiety-like behavior (decreased use of the upper section of the aquarium) in comparison to fish fed twice a day, but feeding four or six times per day or only every second day did not result in differences from feeding twice a day. Feeding frequency had no effect on activity level. Metabolically, fish fed once a day presented decreased levels of glucose and glycogen and increased lactate when compared to the regular feeding (fish fed twice a day), suggesting that feeding regimen may modulate carbohydrate metabolism. Mechanistically, we suggest that the metabolic changes caused by the feeding regimen may induce behavioral changes. Our results suggest that the high variability of the results among different laboratories might be related to different feeding protocols. Therefore, if issues pertaining to the feeding regimen are not considered during experiments with zebrafish, erroneous interpretations of datasets may occur.

3.
Zebrafish ; 14(1): 51-59, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27672711

RESUMO

In this study, we show that an adaptation of the spinning test can be used as a model to study the exercise-exhaustion-recovery paradigm in fish. This forced swimming test promotes a wide range of changes in the hypothalamus-pituitary-interrenal axis functioning, intermediary metabolism, as well in fish behavior at both exercise and recovery periods. Our results pointed that this adapted spinning test can be considered a valuable tool for evaluating drugs and contaminant effects on exercised fish. This can be a suitable protocol both to environmental-to evaluate contaminants that act in fish energy mobilization and recovery after stressors-and translational perspectives-effects of drugs on exercised or stressed humans.


Assuntos
Glucose/análise , Hidrocortisona/análise , Condicionamento Físico Animal/métodos , Natação , Peixe-Zebra/fisiologia , Animais , Comportamento Animal , Creatina Quinase/análise , Metabolismo Energético , Modelos Animais , Estresse Fisiológico , Peixe-Zebra/sangue
4.
Artigo em Inglês | MEDLINE | ID: mdl-27778069

RESUMO

In fish, defensive reactions are induced by different chemical cues that emanate from sense-related stresses [physical, chemical, and visual (visual contact with predator)] or food stresses (acute fasting and chronic food restriction). Using a shuttle box with a two-chamber unmixed laminar flow that allowed fish to remain or flee from a chemical cue, we showed that the avoidance response depended on the type of the chemical cue. We show that zebrafish (Danio rerio) retreated from water conditioned with chemical cues released by chemically or physically stressed fish and acutely fasted fish, but not from water with cues from fish experiencing visual contact with predatory fish or fish suffering from chronic food restriction. Our data reinforced the hypothesis that fish use a combination of information and the context of the situation to determine their evasion strategy.


Assuntos
Água/química , Peixe-Zebra , Animais , Aprendizagem da Esquiva/fisiologia , Comportamento de Escolha , Sinais (Psicologia) , Privação de Alimentos/fisiologia , Comportamento Predatório/fisiologia , Estresse Fisiológico/fisiologia , Natação , Percepção Visual , Peixe-Zebra/fisiologia
5.
Chemosphere ; 112: 85-91, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25048892

RESUMO

We studied the stress response of Rhamdia quelen fingerlings at 45, 90, 135 and 180 d following acute exposure to agrichemicals. Herein, we report the novel observation that acute exposure of fingerling-aged fish to a methyl parathion-based insecticide (MPBI) and to a tebuconazole-based fungicide (TBF) induced chronic inhibition of the stress response. In contrast, fish exposed to an atrazine-simazine-based herbicide (ASBH) recovered the stress response on day 45, and fish exposed to a glyphosate-based herbicide (GBH) did not present stress response inhibition. Additionally, fish exposed to MPBI, GBH and ASBH showed lower survival rates and attained lower final weights. In the case of TBF, the presence of the stressful stimulus more strongly influenced the changes in the performance parameters than did the agrichemical exposure itself. An impairment of the cortisol response may seriously hamper the adaptive response and the ability to promote the necessary metabolic and ionic adjustments to respond to environmental stress.


Assuntos
Peixes-Gato/fisiologia , Hidrocortisona/antagonistas & inibidores , Praguicidas/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Metil Paration/toxicidade , Taxa de Sobrevida , Fatores de Tempo
6.
PLoS One ; 8(10): e74499, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24098336

RESUMO

In southern South America and other parts of the world, aquaculture is an activity that complements agriculture. Small amounts of agrichemicals can reach aquaculture ponds, which results in numerous problems caused by oxidative stress in non-target organisms. Substances that can prevent or reverse agrichemical-induced oxidative damage may be used to combat these effects. This study includes four experiments. In each experiment, 96 mixed-sex, 6-month-old Rhamdia quelen (118±15 g) were distributed into eight experimental groups: a control group that was not exposed to contaminated water, three groups that were exposed to various concentrations of bee products, three groups that were exposed to various concentrations of bee products plus tebuconazole (TEB; Folicur 200 CE™) and a group that was exposed to 0.88 mg L(-1) of TEB alone (corresponding to 16.6% of the 96-h LC50). We show that waterborne bee products, including royal jelly (RJ), honey (H), bee pollen (BP) and propolis (P), reversed the oxidative damage caused by exposure to TEB. These effects were likely caused by the high polyphenol contents of these bee-derived compounds. The most likely mechanism of action for the protective effects of bee products against tissue oxidation and the resultant damage is that the enzymatic activities of superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) are increased.


Assuntos
Antioxidantes/farmacologia , Abelhas/metabolismo , Peixes-Gato/metabolismo , Fungicidas Industriais/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Triazóis/toxicidade , Animais , Mel/análise , Pólen/metabolismo
7.
Artigo em Inglês | MEDLINE | ID: mdl-18824247

RESUMO

As in many aquatic environments, pollution is a widespread problem in Southern Brazil. In our previous work, we demonstrated that sublethal contamination with some agrichemicals impairs the capacity of fishes to elevate cortisol levels in response to an additional acute stressor. In earlier experiments, the experimental design did not allow us to conclude where this effect occurs. In the present work, we used the adrenocorticotropic hormone (ACTH) challenge test to help us identify if the impairment occur in the interrenal tissue. For this purpose, five experiments were conducted, each with one specific agrichemical (methyl-parathion, atrazine+simazine, atrazine, tebuconazole, and glyphosate) in sublethal concentrations of 16.6% of the LC(50-96h), as previously determined. Fish were subjected to the ACTH challenge test protocol as follows: group 1, were non-injected and maintained as the specific control group; group 2 received an injection of the vehicle alone (the saline group); and group 3 receive an injection of ACTH. One hour later, blood samples were taken from the caudal plexus, using sterile syringes. In all specific control groups, the injection of ACTH induced a strong rise in plasma cortisol, compared with the fish injected only with the vehicle and the non-injected group. Fish exposed to methyl-parathion and tebuconazole did not elevate cortisol in response to the ACTH injection, with values significantly lower than the control fish. Fish exposed to sublethal concentrations of atrazine+simazine, atrazine, and glyphosate showed a rise in plasma cortisol very similar to the control fish. We conclude that the ACTH challenge test revealed that R. quelen exposed to sublethal concentrations of tebuconazole and methyl-parathion had a reduced ability to elevate plasma cortisol in response to an intraperitoneal (i.p.) injection of exogenous ACTH, indicating that the interrenal tissue is the site of the impairment within the HPI axis. These ACTH challenge tests also revealed that the impairment of the cortisol response verified in fish exposed to atrazine+simazine and glyphosate, as shown in our previous work, seems to be related to steps of cortisol secretion in higher levels within the HPI axis.


Assuntos
Hormônio Adrenocorticotrópico/administração & dosagem , Agroquímicos/toxicidade , Peixes-Gato/sangue , Disruptores Endócrinos/toxicidade , Hidrocortisona/sangue , Glândula Inter-Renal/efeitos dos fármacos , Testes de Função Adreno-Hipofisária , Poluentes Químicos da Água/toxicidade , Animais , Atrazina/toxicidade , Feminino , Glicina/análogos & derivados , Glicina/toxicidade , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Injeções Intraperitoneais , Glândula Inter-Renal/metabolismo , Masculino , Metil Paration/toxicidade , Simazina/toxicidade , Triazóis/toxicidade
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