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1.
Chemosphere ; 244: 125546, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050342

RESUMO

Selenium (Se) is the most common micronutrient and that becomes toxic when present at higher concentrations in aquatic environments. Astaxanthin (AST) has been documented to possess antioxidant and anti-inflammatory properties. The aim of this study was to explore the potential of dietary AST and Se exposure on oxidative stress, and inflammatory response in Channa argus. After acclimation, 540 fish were randomly distributed into nine groups housed in twenty-seven glass tanks. The fish were exposed for 8 weeks to waterborne Se at 0, 100 and 200 µg L-1 or dietary AST at 0, 50 and 100 mg kg-1. The results shown that Se accumulation in the kidney, liver, spleen, intestine and gill were significantly increased following Se exposure, dietary 50 and 100 mg kg-1 AST supplementation decreased the accumulation of Se in the kidney, liver, spleen, and intestine. In addition, AST supplementation can decrease oxidative stress and inflammatory response in the liver and spleen following exposure to waterborne Se. These results indicate that AST has the potential to alleviate the effects of Se toxicity in C. argus.


Assuntos
Peixes/fisiologia , Selênio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Bioacumulação , Dieta , Brânquias/metabolismo , Rim/metabolismo , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Selênio/metabolismo , Baço , Xantofilas/toxicidade
2.
Dis Aquat Organ ; 138: 41-88, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32103822

RESUMO

The hepatopancreas of decapod crustaceans is used as an example to illustrate the range of cytopathologies, detoxification mechanisms, and immune responses that environmental toxicants and pathogens can induce in a single organ. The hepatopancreas is the central metabolic organ of decapods and consists of hundreds of blindly-ending tubules and intertubular spaces. The tubular epithelium contains 5 structurally and functionally different cell types, and the interstitium contains haemolymph, haemocytes, connective tissue, and fixed phagocytes. Some physiological conditions such as moulting and starvation cause marked but reversible ultrastructural alterations of the epithelial cells. Environmental toxicants induce either detoxification mechanisms or structural damage in cells, depending on toxicant and concentration. The hepatopancreas is also a main target organ for pathogens, mainly viruses, bacteria, and protists that enter the body via the digestive tract and gills and replicate in the hepatopancreatocytes. The cytopathologies caused by toxicants and pathogens affect single cell types specifically or, more often, several cell types simultaneously. Pathogenesis often begins in a certain cell organelle such as the nucleus, mitochondrion, or endoplasmic reticulum, spreads to other organelles, and ends with death of the infected cell. Fixed phagocytes in the interstitium capture and degrade pathogens that move from the infected tubules into the intertubular spaces or enter the hepatopancreas via circulation. Relatively few disease agents elicit the melanisation and encapsulation reaction that encloses infected tubules by a rigid melanised capsule and kills the entrapped pathogens.


Assuntos
Animais , Brânquias , Hemolinfa , Hepatopâncreas
3.
Chemosphere ; 242: 125229, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896198

RESUMO

The objective was to determine the median lethal concentration (LC50) of nitrate for post-larvae and juveniles of Macrobrachium amazonicum exposed for 96 h, and to identify histopathological alterations in the gills of juveniles exposed to nitrate. Post-larvae and juveniles of M. amazonicum were exposed to seven different concentrations of nitrate (0, 50, 100, 500, 1000, 1500 and 2000 mg.L-1) with four replicates (n = 10 prawn/experimental unit). The degree of damage to the branchial structure of juveniles was evaluated using standard histological processing with hematoxylin and eosin (H&E), subjected to the Organ Index (Iorg). LC50 values at 24, 48, 72 were estimated by the Trimmed Spearman Karber Method software and were respectively 1574, 638, 237, and 194 mg.L-1 for post-larvae and 1070, 286, 185 and 155 mg.L-1 for juveniles, respectively. From these results, the safety level of nitrate was estimated at 157, 64, 24 and 19 mg.L-1 for post-larvae and 107; 27; 18 and 16 mg.L-1 for juveniles, respectively for 24 h, 48 h, 72 h and 96 h. Damage to the gills in treatments with 100% mortality for nitrate corresponded to the high occurrence of progressive, regressive, circulatory and inflammatory damages. The other treatments, which caused lower mortality, mainly resulted in inflammation and regressive damage, whose occurrence increased with increasing concentration of nitrate. However, in closed systems, the use of anaerobic denitrifying filters or aquatic macrophytes is necessary to provide suitable water quality for the best productive performance, avoiding the negative influence of the accumulated nitrate.


Assuntos
Nitratos/toxicidade , Palaemonidae/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Brânquias/patologia , Larva , Dose Letal Mediana , Testes de Toxicidade Aguda
4.
J Parasitol ; 106(1): 53-55, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31995718

RESUMO

A new species of monogenean, Dactylogyrus pisolabrae n. sp., was found parasitizing the gills of the Pealip Redhorse, Moxostoma pisolabrum, from Oklahoma. Dactylogyrus pisolabrae is morphologically similar to Dactylogyrus apos, Dactylogyrus atripinnei, Dactylogyrus duquesnei, and Dactylogyrus niger, all parasitizing other species of suckers, by possessing a robust, sickle-shaped male copulatory organ, but differs from these and all other species of North American Dactylogyrus by possessing 2 unique wing-like projections opposite each other on the proximal portion of the accessory piece. Dactylogyrus pisolabrae represents the first monogenean reported from the Pealip Redhorse.


Assuntos
Cipriniformes/parasitologia , Doenças dos Peixes/parasitologia , Platelmintos/isolamento & purificação , Infecções por Trematódeos/veterinária , Animais , Doenças dos Peixes/epidemiologia , Brânquias/parasitologia , Masculino , Oklahoma/epidemiologia , Platelmintos/anatomia & histologia , Platelmintos/classificação , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
5.
Mar Pollut Bull ; 150: 110743, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31910517

RESUMO

Copper (Cu) is an essential metal capable to alter many metabolic and physiological processes in animal species, depending on the environmental concentration and salinity. The present study evaluated the effects of Cu exposure on the metabolism of the blue crab Callinectes sapidus under different osmotic situations. Crabs were acclimated at two different salinities conditions (30 and 2). Subsequently, they were exposed to Cu during 96 h at each salinity and under hypo-osmotic shock. Results demonstrated that Cu exposure increased whole-body oxygen consumption. In addition, the activity of LDH decreased while citrate synthase increased in anterior gills from animals submitted to hypo-osmotic shock. This scenario indicates extra stress caused by sudden environmental osmotic changes, as commonly observed in estuarine environments, when combined with copper exposure. Therefore, the activity of LDH and citrate synthase enzymes might be sensitive indicators for aquatic toxicology studies approaching Cu contamination in estuarine environments.


Assuntos
Braquiúros/fisiologia , Cobre/toxicidade , Metabolismo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Braquiúros/metabolismo , Brânquias , Pressão Osmótica/fisiologia , Salinidade
6.
Ecotoxicol Environ Saf ; 190: 110119, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891835

RESUMO

Chlorothalonil is an effective fungicide used in agriculture and formulations of antifouling paints, which use and possible toxicity has been generating great concern. Thus, the present study investigated the effects of chlorothalonil on the antioxidant defense system (ADS) of the mussel Perna perna. The ADS was evaluated in gills and digestive gland after 24 h and 96 h of exposure to environmental relevant levels of chlorothalonil (0.1 and 10 µg/L). The activity of the enzymes superoxide dismutase (SOD), catalase (CAT), glutamate cysteine-ligase (GCL) and glutathione S-transferase (GST), levels of non-enzymatic defenses, represented by glutathione (GSH), and lipoperoxidation (LPO) and protein carbonyls (PCO) were evaluated. Results indicated that exposure to chlorothalonil is affecting the ADS in both tissues. While the activity of SOD increased and GST and GSH were not altered in gills, they decreased in digestive gland after 24 h of exposure to 10 µg/L of chlorothalonil. The contrasting results indicate that gills and digestive gland presented different patterns of responses after exposure to chlorothalonil. Moreover, a tissue-specific response to chlorothalonil was observed. Gills could be acting as the first line of defense, presenting higher enzymatic levels with minor effects on the parameters analyzed. On the other hand, digestive gland, with lower levels of antioxidant defenses, was the most affect organ by chlorothalonil. It also should be highlighted that the fungicide reduced the glutathione metabolism in the digestive gland, which can lead to an imbalance of the redox state within the cells of animals.


Assuntos
Antioxidantes/metabolismo , Fungicidas Industriais/toxicidade , Nitrilos/toxicidade , Perna (Organismo)/fisiologia , Animais , Catalase/metabolismo , Fungicidas Industriais/metabolismo , Brânquias/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Perna (Organismo)/efeitos dos fármacos , Superóxido Dismutase/metabolismo
7.
Ecotoxicol Environ Saf ; 190: 110107, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31901814

RESUMO

Increased malondialdehyde (MDA) levels are commonly considered an indicator of lipid peroxidation derived from oxidative stress insults promoted by exposure of fish to pollutants. However, a decrease in MDA levels after xenobiotic exposure has been also reported, an effect that is mostly attributed to enhanced antioxidant defenses. In this study, we assessed whether pollutant-mediated MDA decrease would be associated with antioxidant enhancement or with its metabolism by aldehyde dehydrogenase (ALDH) in the liver and gills of lambari (Astyanax altiparanae) exposed to diesel oil (0.001, 0.01, and 0.1 mL/L). MDA levels were decreased in the liver of lambari exposed to diesel. The activities of the antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), were unchanged in the liver, while that of glucose-6-phosphate dehydrogenase (G6PDH) was decreased. In contrast, levels of total glutathione (tGSH) and the activity of glutathione S-transferase (GST) were increased in the liver, which partly support antioxidant protection against lipid peroxidation. More importantly, ALDH activity increased in a concentration-dependent manner, being negatively correlated with MDA levels, indicating MDA metabolism by ALDH. In the gills, diesel exposure increased MDA and lipid hydroperoxide levels, and promoted increases in antioxidant defenses, indicating oxidative stress. Curiously, ALDH activity was undetectable in the gills, supporting the possibility of direct MDA excretion in the water by the gills. Analyses of MDA in the water revealed increased levels of MDA in the aquaria in which the fish were exposed to diesel, compared to control aquaria. A second experiment was carried out in which the fish were intraperitoneally injected with MDA (10 mg/kg) and analyzed after 1, 6, and 12 h. MDA injection caused a time-dependent decrease in hepatic MDA levels, did not alter ALDH, CAT, GPx, and GST activities, and decreased G6PDH activity and tGSH levels. In the gills, MDA injection caused a slight increase in MDA levels after 1 h, but did not alter GPx, G6PDH, and GST activities. MDA injection also enhanced CAT activity and tGSH levels in the gills. MDA concentration in water increased progressively after 1, 6, and 12 h, supporting the hypothesis of direct MDA excretion as an alternative route for MDA elimination in fish. Our results suggest that the decreased MDA levels after exposure of lambari to diesel oil pollutant probably reflects an association between enhanced antioxidant protection, MDA metabolism, and MDA excretion in water.


Assuntos
Aldeído Desidrogenase/metabolismo , Peixes/metabolismo , Gasolina/toxicidade , Malondialdeído/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Characidae/metabolismo , Brânquias/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Estresse Oxidativo , Alimentos Marinhos , Poluentes Químicos da Água/metabolismo
8.
Environ Pollut ; 256: 113504, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31706775

RESUMO

Although the toxicity of silver nanoparticles (AgNPs) in aquatic organisms has been extensively investigated, the mechanism by which AgNPs damage membranes remains unclear. This study investigated the toxic effects of a series of sub-lethal concentrations of AgNPs on the membranes of freshwater carp (Cyprinus carpio) gills, based on changes in membrane fatty acid (FA) profile, membrane fluidity, membrane lipid peroxidation, and histopathology. Most of the FAs in fish gill membrane was not significantly affected by exposure to multiple AgNPs concentrations, only few significant changes occurred in some specific FAs species at a high concentration of AgNPs exposure. In particular, high concentrations of AgNPs significantly decreased the proportions of two important long-chain n-3 series polyunsaturated FAs (C20: 5n3, and C22: 6n3), resulting in a decreased ratio of n-3 polyunsaturated FAs to n-6 polyunsaturated FAs (Σn-3UFA/Σn-6UFA). The AgNPs also caused a dose-dependent decrease in fish gill membrane fluidity, increased the level of lipid peroxidation, and inhibited Na+/K+-ATPase enzyme activity. Further histopathological examination revealed that exposure to AgNPs can cause toxic responses in the lamellae, including the thinning of the basement membrane, malformation, and inflammation. Together, the results suggest that the mechanism of AgNPs membrane toxicity involves the oxidization of long-chain omega-3 unsaturated FAs to saturated FAs via lipid peroxidation, resulting in, decreased membrane fluidity and ultimately the destruction of the normal physiological function of the fish gill membrane. The findings contribute significantly to our understanding of nanoparticle-induced membrane toxicity and potential risks in aquatic environments.


Assuntos
Carpas/fisiologia , Brânquias/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Ácidos Graxos/metabolismo , Brânquias/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos
9.
Aquat Toxicol ; 218: 105358, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31805486

RESUMO

Mangroves are tidal wetlands that are often under strong anthropogenic pressures, despite the numerous ecosystem services they provide. Pollution from urban runoffs is one such threats, yet some mangroves are used as a bioremediation tool for wastewater (WW) treatment. This practice can impact mangrove crabs, which are key engineer species of the ecosystem. Using an experimental area with controlled WW releases, this study aimed to determine from an ecological and ecotoxicological perspective, the effects of WW on the red mangrove crab Neosarmatium africanum. Burrow density and salinity levels (used as a proxy of WW dispersion) were recorded, and a 3-week caging experiment was performed. Hemolymph osmolality, gill Na+/K+-ATPase (NKA) activity and gill redox balance were assessed in anterior and posterior gills of N. africanum. Burrow density decreased according to salinity decreases around the discharged area. Crabs from the impacted area had a lower osmoregulatory capacity despite gill NKA activity remaining undisturbed. The decrease of the superoxide dismutase activity indicates changes in redox metabolism. However, both catalase activity and oxidative damage remained unchanged in both areas but were higher in posterior gills. These results indicate that WW release may induce osmoregulatory and redox imbalances, potentially explaining the decrease in crab density. Based on these results we conclude that WW release should be carefully monitored as crabs are key players involved in the bioremediation process.


Assuntos
Braquiúros/efeitos dos fármacos , Monitoramento Ambiental/métodos , Águas Residuárias/toxicidade , Poluentes Químicos da Água/toxicidade , Áreas Alagadas , Animais , Biodegradação Ambiental , Braquiúros/fisiologia , Ecossistema , França , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Hemolinfa/efeitos dos fármacos , Ilhas do Oceano Índico , Oxirredução , Salinidade , ATPase Trocadora de Sódio-Potássio/metabolismo , Águas Residuárias/química
10.
Aquat Toxicol ; 218: 105333, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31783301

RESUMO

In the current study, to investigate the effect of imidacloprid on benthic bivalves, adult Asian clams (Corbicula fluminea) were exposed to 0, 20, 200, and 2000 µg/L imidacloprid for 30 d. Imidacloprid significantly inhibited the siphoning and burrowing behaviour (p < 0.05) of the clams. Significant histopathological changes were associated with degeneration of the cilium, the contraction and adhesion of the lymphocyte, and the swelling of epithelium cells in gills, and there was notable degeneration in the digestive tubules, haemolytic infiltration in the connective tissue and epithelial cell necrosis in the digestive glands in the 2000 µg/L treatment group. The activity of AChE in the digestive glands was significantly inhibited at all treatment levels, whereas this inhibition was observed in gills only in the 2000 µg/L treatment (p < 0.05). Additionally, indicators of the antioxidant system (e.g., SOD, CAT, and GST activity) and MDA content were significantly increased in the gills and digestive glands with all treatments (p < 0.05). Moreover, the mRNA expression levels of Hsp genes (hsp 22, hsp 40, hsp 60, hsp 70, hsp 90) and multixenobiotic resistance (MXR) system-related genes (abcb1, abcc1) were significantly downregulated (p < 0.05). Therefore, our results suggest that imidacloprid changes the oxidative stress, cellular detoxification, and MXR system of C. fluminea. Our findings provide new insights into the effects of neonicotinoids on benthic bivalves such as C. fluminea.


Assuntos
Antioxidantes/metabolismo , Corbicula/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Poluentes Químicos da Água/toxicidade , Xenobióticos/toxicidade , Animais , Corbicula/genética , Corbicula/metabolismo , Relação Dose-Resposta a Droga , Resistência a Múltiplos Medicamentos/genética , Água Doce/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/patologia , Estresse Oxidativo/efeitos dos fármacos
11.
Aquat Toxicol ; 218: 105362, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31783303

RESUMO

Nitrite is a major environmental pollutant in aquatic environments that negatively affects aquatic species. In this study, we investigated the impact of nitrite exposure on plasma biochemical parameters and immune responses in Takifugu rubripes. Fish were exposed to various concentrations of nitrite (0, 0.5, 1, 3, and 6 mM) for 96 h. After 0, 12, 24, 48, and 96 h of exposure, fish blood samples were collected to assay the levels of total protein (TP), albumin (Alb), glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (ALT), complement C3 (C3), complement C4 (C4), immunoglobulin (IgM), and lysozyme activity (LZM). The gills were sampled to analyze the mRNA levels of heat shock protein 70 (hsp70), heat shock protein 90 (hsp90), tumor necrosis factor α (tnf-α), B-cell activating factor (baff), interleukin-6 (il-6), and interleukin-12 (il-12). Levels of GOT, ALT, C3, and C4 were significantly enhanced in the high nitrite concentration group (3 and 6 mM), whereas those of TP, Alb, LZM, and IgM decreased significantly with the same treatments. Nitrite significantly upregulated hsp70, hsp90, tnf-α, il-6, il-12, and baff mRNA levels after 96 h of exposure. These results indicated that nitrite exposure altered the blood physiological status and immune system response, resulting in dysfunction and immunotoxicity in T. rubripes. Furthermore, our results reveal the possible mechanism of aquatic-nitrite-induced toxicity in fish.


Assuntos
Citocinas/sangue , Proteínas de Peixes/sangue , Imunidade Humoral/efeitos dos fármacos , Nitritos/toxicidade , Takifugu , Poluentes Químicos da Água/toxicidade , Animais , Citocinas/genética , Proteínas de Peixes/genética , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Takifugu/sangue , Takifugu/imunologia , Transcrição Genética/efeitos dos fármacos
12.
Aquat Toxicol ; 218: 105348, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31812647

RESUMO

Various strategies exist to control noxious cyanobacterial populations, although the application of a newly developed granular compound (sodium carbonate peroxyhydrate 'SCP', trade name 'PAK® 27' algaecide) containing hydrogen peroxide (H2O2) as the active ingredient, has been recently proven as an effective and ecofriendly treatment. However, in aquaculture settings the application of SCP to treat cynobacterial blooms may affect non-targeted biota, such as fish due to H2O2 being known to elicit toxic oxidative stress. Consequently, a better understanding of the side effects as a function of dosing concentrations would help to improve treatment efficacy and fish welfare. Thus, the aim of the current study is to assess the potential risks of SCP to largemouth bass (Micropterus salmoides), a high priced fish in the U.S. To this end, fish were exposed to two recommended doses of SCP corresponding to either 2.5 or 4.0 mg/L H2O2 for 6 days, with a control group in parallel. After 6 days, the effect of SCP exposure on oxidative stress, histopathological changes and anti-oxidant potential in the brain, liver, gills and muscle were investigated. Results show that exposure to 4.0 mg/L H2O2 -SCP incited oxidative damage, evidenced by an over-accumulation of H2O2 and malondialdehyde (MDA) in the brain and liver, which were accompanied by an increment in xanthine oxidase activity. Unlike 4.0 mg/L H2O2, these oxidative stress biomarkers in the brain and liver tissue of 2.5 mg/L H2O2-SCP exposed fish were restrained within control levels and concomitant with an increase in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-s-transferase (GST) activity. In contrast, many of these anti-oxidants sentinels in the 4.0 mg/L H2O2 exposed fish were either unaffected or significantly inhibited, which resulted in over-accumulation of H2O2 and MDA. In addition, a series of histopathological alterations were observed, and the most severe brain injuries and liver inflammation were recorded in 4.0 mg/L H2O2-SCP exposed fish. Based on oxidative parameters, both SCP doses resulted in a relatively mild oxidative stress in gills but no effect in muscle, probably explaining the modest anti-oxidative responses in the former and almost complete lack of anti-oxidative responses in the latter. Overall, our findings suggests that the application of SCP at 4.0 mg/L H2O2 to control cyanobacterial blooms in aquaculture settings can possess potential risks to the farmed fish.


Assuntos
Bass/metabolismo , Carbonatos/toxicidade , Herbicidas/toxicidade , Peróxido de Hidrogênio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Carbonatos/química , Cianobactérias/efeitos dos fármacos , Eutrofização/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Herbicidas/química , Peróxido de Hidrogênio/química , Fígado/efeitos dos fármacos , Fígado/enzimologia , Poluentes Químicos da Água/química
13.
Ecotoxicol Environ Saf ; 188: 109878, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704330

RESUMO

In the present study, we evaluated the effects of nitrite exposure on hematological parameters, oxidative stress, and apoptosis in juvenile Takifugu rubripes. The fish were exposed to nitrite (0, 0.5, 1, 3, and 6 mM) for up to 96 h. In the high nitrite concentration groups (i.e., 3 and 6 mM), the concentrations of methemoglobin (MetHb), cortisol, glucose, heat shock protein (Hsp)-70, Hsp-90, and potassium (K+) were significantly elevated. Whereas, the concentrations of hemoglobin (Hb), triglyceride (TG), total cholesterol (TC), and sodium (Na+) and chloride (Cl-) ions were significantly decreased. Compared with those of the control groups, the concentrations of the antioxidant enzymes, namely, superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx), in the gills were considerably elevated at 12 and 24 h after exposure to nitrite (1, 3, and 6 mM), but reduced at 48 and 96 h. The increase in the antioxidant enzymes may contribute to the elimination of reactive oxygen species (ROS) induced by nitrite during early nitrite exposure, when the antioxidant system is not sufficiently effective to eliminate or neutralize excessive ROS. In addition, we found that nitrite exposure could alter the expression patterns of some key apoptosis-related genes (Caspase-3, Caspase-8, Caspase-9, p53, Bax, and Bcl-2). This indicated that the caspase-dependent apoptotic pathway and p53-Bax-Bcl-2 pathway might be involved in apoptosis induced by nitrite exposure. Furthermore, our study provides insights into how acute nitrite exposure affects the physiological responses and potential molecular mechanism of apoptosis in marine fish. The results can help elucidate the mechanisms involved in nitrite-induced aquatic toxicology in marine fish.


Assuntos
Apoptose/efeitos dos fármacos , Nitritos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Takifugu/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Takifugu/metabolismo , Testes de Toxicidade Aguda , Poluentes Químicos da Água/metabolismo
14.
Ecotoxicol Environ Saf ; 188: 109890, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704321

RESUMO

The present study evaluated the adverse effects of the hexavalent chromium (Cr (VI)) at sub-lethal concentrations and the ameliorative potential of curcumin (CUR) over a sub-chronic exposure period on Oreochromis niloticus. Fish were exposed to Cr (VI) (4.57 mg/L) and CUR (0.02% in diet or 200 mg/kg diet), individually or in combination for 60-days. The growth rate during the period of experiment, condition factor, body composition, hepatosomatic index (HSI), hematological parameters, oxidative stress, apoptotic and DNA damage, branchial, hepato- and nephrotoxicity were estimated in this study. Moreover, the changes in mRNA expression of Cytochromes (CYP450) and glutathione S-transferase (GST) in kidney and liver tissues were assessed by qRT-PCR. Additionally, the concentration of metallothionine in the liver, histological investigation, and lesion scoring to the branchial, hepatic, renal and gill tissues were applied. The results revealed that Cr (VI) exposure caused a significant decline in most hematological variables and growth rate with down-regulation of CYP450 and GST expression. Histologically, Cr (VI) induced diverse forms of cell injury, vascular, and inflammatory alterations with upregulation of caspase-3 and downregulation of Bcl2 expression in the examined tissues. Additionally, it elevated the levels of serum MDA and 8-hydroxy-2' -deoxyguanosine than control. CUR-supplementation resulted in a significant improvement in most indices, amelioration of histological alterations and up-regulation of CYP450 and GST expression. These results may conclude that dietary supplements with CUR could be useful for modulation of the growth with protective effects to the branchial, hepatic, and renal tissues in response to Cr (VI) exposure, thereby presenting a promising feed additive for Nile tilapia in aquaculture.


Assuntos
Cromo/toxicidade , Ciclídeos/metabolismo , Curcumina/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Glutationa Transferase/genética , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Aquicultura , Ciclídeos/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Suplementos Nutricionais , Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Glutationa Transferase/metabolismo , Rim/enzimologia , Fígado/enzimologia , Estresse Oxidativo/efeitos dos fármacos
15.
Gene ; 722: 144101, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31479714

RESUMO

The catadromous species, eels, invariably exposed to variable Ca2+ concentrations circumstance i.e., lagoon or ocean. They need to maintain Ca2+ homeostasis by exchanging Ca2+ under different culture conditions. To understand the effects of environmental Ca2+ to fish, three types of genes coding for voltage-dependent L-type calcium channels (cacnb1, 2, 3) were cloned by screening an A. marmorata cDNA library. Tissue distribution analysis of Western blot showed that Cacnb1, 2, 3 had a significantly high expression in gill; while mRNA results showed the expressions of cacnb1 and cacnb3 were predominated in skin tissue but only cacnb2 was expressed in intestine. Serum osmolality and Ca2+ concentrations of A.marmorata were increased in a high calcium environment while reduced in a low calcium environment within 7 days; however, they were not significantly different among Ca2+ treatments after the eels were acclimated for 7 days. We also examined the influence of ambient Ca2+ levels on cacnbs expression of eels. With the increasing of exposure time, mRNA and protein expressions of cacnb1 were up-regulated in high level of Ca2+ (10 mM) and down-regulated in deficient Ca2+ (0 mM) compared to the control Ca2+ (2 mM). However, the opposite results were observed in cacnb2 and cacnb3. Notably, the cacnb2 expression was not significant different among Ca2+ treatments on day 7. Our study provided the insightful evidence that cacnbs play important roles in maintaining Ca2+ homeostasis of fish.


Assuntos
Anguilla/metabolismo , Canais de Cálcio Tipo L/metabolismo , Cálcio/fisiologia , Aclimatação , Anguilla/sangue , Anguilla/genética , Animais , Cálcio/sangue , Canais de Cálcio Tipo L/química , Canais de Cálcio Tipo L/genética , Clonagem Molecular , Brânquias/metabolismo , Concentração Osmolar , RNA Mensageiro/metabolismo , Distribuição Tecidual
16.
Artigo em Inglês | MEDLINE | ID: mdl-31669372

RESUMO

The razor clam Sinonovacula constricta is a commercial benthic bivalve, and burrows the deeper cave than the other buried benthic bivalves. Due to the little exchange of seawater and to anoxic conditions, S. constricta is exposed to considerable amounts of sulfide during low tide, but exhibits strong sulfide tolerance. Mitochondrial sulfide oxidation is a particular defense strategy against sulfide toxicity of sulfide-tolerant organisms, for which sulfide:quinone oxidoreductase (SQR) is the first key enzyme. In order to investigate the mechanism of sulfide tolerance in S. constricta, its SQR (designated as ScSQR), was cloned and characterized. The full-length cDNA of ScSQR was 3698 bp and encoded 443 amino acids. The deduced ScSQR protein contained conserved FAD-binding domains, two cysteine residues, two histidines, and one glutamic acid, which are the essential elements for the catalytic mechanism of SQR. Subcellular localization analysis by the TargetP 1.1 prediction and the Western blot confirmed that ScSQR was only located in the mitochondria. The response of ScSQR in the gill and liver of S. constricta were investigated during sulfide exposure (50, 150, and 300 µM sulfide) for 0, 3, 6, 12, 24, 48, 72, and 96 h by qRT-PCR. Moreover, the time-course expressions of ScSQR protein in the S. constricta gill were detected when exposed to 150 µM sulfide by Western blot. The expression level of ScSQR increased significantly and showed a time-dependent pattern. In addition, under sulfide stress, the expression level of the gill was higher than that of liver. Together, our results suggest that ScSQR may perform important roles in protecting cells from sulfide stress by participating in mitochondrial sulfide detoxification and providing high sulfide tolerance to S. constricta.


Assuntos
Bivalves/embriologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Quinona Redutases/biossíntese , Estresse Fisiológico/efeitos dos fármacos , Sulfetos/farmacologia , Animais , Brânquias/enzimologia , Fígado/enzimologia
17.
Chemosphere ; 239: 124767, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518925

RESUMO

The present study analyzed the Peruvian scallop Argopecten purpuratus and its food sources for metal and fatty acid concentrations in order to determine spatial and temporal differences. Metals such as copper (Cu), manganese (Mn), and zinc (Zn) in gills and iron (Fe) and Zn in sediments were the most significant explaining factors for spatial differentiations (degree of contamination), while for fatty acids, it was C14:0, C15:0, C16:0 and C18:0 in A. purpuratus' muscle and in its food sources, which explained more temporal differences (El Niño-Southern Oscillation (ENSO) effect). Gills, digestive gland and intestine were the tissues where metal accumulation was the highest in A. purpuratus. Cd in digestive gland was always high, up to ∼250-fold higher than in other tissues, as previously reported in other bioindicator species for metal pollution. Fatty acids were good biomarkers when annual comparisons were performed, while metals when locations were compared. ENSO 2017 played an important role to disentangle A. purpuratus' biological conditions and food sources. A. purpuratus from Paracas locations mostly showed higher metal concentrations in gills and digestive glands, and lower fatty acid concentrations in muscle than those from Sechura and Illescas Reserved Zone.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Pectinidae/química , Poluentes Químicos da Água/análise , Animais , Aquicultura , Cobre/análise , Cobre/farmacocinética , Biomarcadores Ambientais , Ácidos Graxos/análise , Brânquias/química , Ferro/análise , Ferro/farmacocinética , Manganês/análise , Manganês/farmacocinética , Músculos/química , Pectinidae/metabolismo , Peru , Frutos do Mar/análise , Análise Espaço-Temporal , Distribuição Tecidual , Zinco/análise , Zinco/farmacocinética
18.
Chemosphere ; 238: 124586, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31442775

RESUMO

Cyantraniliprole can effectively control lepidopteran pests and has been used all over the world. In general, the risk of cyantraniliprole seems low for fish, but the toxicity selectivity among different fish species was not clear. Here the acute toxicity and chronic effects of cyantraniliprole to juvenile tilapia (Oreochromis mossambicus) were assessed. The results showed that 96 h LC50 of cyantraniliprole to tilapia was 38.0 mg/L. After exposed for 28 days, specific growth rates of the blank control, solution control, and the treatments of 0.037, 0.37 and 3.7 mg/L of cyantraniliprole were 1.14, 0.95, 0.93, 0.82 and 0.70% per day, respectively. The results of micronucleus experiment and single cell gel electrophoresis showed that cyantraniliprole damaged DNA in liver cells of tilapia larvae. Quantitative PCR results showed that cyantraniliprole could induce the up-regulation of Rpa 3 that is responsible for the DNA repair. The significantly down-regulation of Chk 2 gene was related to p53 pathway. It is therefore proposed that cyantraniliprole causes DNA damage in liver cells of tilapia and activates DNA damage and repair pathways.


Assuntos
Dano ao DNA/efeitos dos fármacos , Inseticidas/toxicidade , Fígado/patologia , Pirazóis/toxicidade , Tilápia/embriologia , Tilápia/crescimento & desenvolvimento , ortoaminobenzoatos/toxicidade , Animais , Quinase do Ponto de Checagem 2/biossíntese , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Proteínas de Ligação a DNA/biossíntese , Brânquias/metabolismo , Hepatócitos/efeitos dos fármacos , Larva , Dose Letal Mediana , Alimentos Marinhos
19.
Chemosphere ; 238: 124588, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31545210

RESUMO

Few works have addressed the effects provoked by the exposure to cadmium containing nanoparticles (NPs) on adult zebrafish (Danio rerio). We studied the effects of CdS NPs (5 nm) or ionic cadmium (10 µg Cd/L) after 3 and 21 d of exposure and at 6 months post-exposure (mpe). Acute toxicity was recorded after exposure to both forms of cadmium. Significant cadmium accumulation was measured in the whole fish after both treatments and autometallography showed a higher accumulation of metal in the intestine than that in the liver. Histopathological alterations, such as inflammation in gills and vacuolization in the liver, were detected after the exposure to both cadmium forms and, in a lower extent, at 6 mpe. X-ray analysis proved the presence of CdS NPs in these organs. The hepatic transcriptome analysis revealed that gene ontology terms such as "immune response" or "actin binding" were over-represented after 21 d of exposure to ionic cadmium respect to CdS NPs treatment. Exposure to CdS NPs caused a significant effect on pathways involved in the immune response and oxidative stress, while the exposure to ionic cadmium affected significantly pathways involved in DNA damage and repair and in the energetic metabolism. Oxidative damage to liver proteins was detected after the exposure to ionic cadmium, while a stronger destabilization of the hepatocyte lysosomal membrane was recorded under exposure to CdS NPs. In summary, although ionic cadmium provoked stronger effects than CdS NPs, both cadmium forms exerted an array of lethal and sublethal effects to zebrafish.


Assuntos
Bioacumulação/fisiologia , Compostos de Cádmio/toxicidade , Cádmio/toxicidade , Sulfetos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Brânquias/metabolismo , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos
20.
Aquat Toxicol ; 219: 105381, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869578

RESUMO

Aquatic ecosystems are subject to many anthropogenic disturbances, and understanding their possible impacts is a real challenge. Developing approaches based on the behaviour of bivalve mollusks, an integrating marker of the state of the organisms, and therefore of their environment, is relevant, whether within a natural ecosystem or an ecosystem subject to industrial activities. The main objective of this study was to identify by HFNI Valvometry a reliable and reproducible clam behavioural response in the presence of crude oil in a multistress context. To closely replicate actual field conditions, Corbicula fluminea was exposed in outdoor artificial streams that were subject to natural variations and were continuously fed by fresh water from the Gave de Pau (S.W. France). After a period of 26 days in these artificial streams, the clams (n = 14-16 per condition) were separately exposed for 10 days to crude oil alone, crude oil and barium, crude oil and noise pollution, crude oil and turbidity pulses, barium alone, noise pollution alone, turbidity pulses alone or natural changes alone. The secondary objective was to characterize the accumulation of polycyclic aromatic hydrocarbons (PAH) in 3 tissues (gills, adductor muscles and foot) in clams exposed for 10 days to crude oil alone or under multistress conditions (n = 5 clams per condition) and then to compare the accumulation and behaviour of clams under these conditions. The response of clams to crude oil alone or under multistress conditions was visually and statistically significant and not confounded by the other disturbances tested, despite large variations in water temperature. In the presence of crude oil, the behaviour of clams was characterized by an increase in valve-closure duration, a decrease in valve-opening amplitude and an increase in valve agitation index. In the presence of crude oil, the clam behaviour showed no direct relationship with PAH accumulation in the gills, adductor muscles or foot, although hypothetical mechanisms are discussed. This work supports the growing interest in studying the behaviour of bivalve mollusks in the context of biomonitoring of the aquatic environment surrounding oil facilities.


Assuntos
Comportamento Animal/efeitos dos fármacos , Corbicula/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Corbicula/metabolismo , Ecossistema , Monitoramento Ambiental/métodos , França , Água Doce/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Modelos Teóricos
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