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1.
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
2.
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
3.
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
4.
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
5.
Physiol Biochem Zool ; 92(6): 554-566, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31567050

RESUMO

Pacific spiny dogfish (Squalus suckleyi) have been widely used as a representative species for chondrichthyan CO2 excretion. Pacific spiny dogfish have a slower red blood cell (RBC) carbonic anhydrase (CA) isoform than teleost fishes, extracellular CA activity, no endogenous plasma CA inhibitor, and plasma-accessible CA IV at the gills. Thus, both the RBC and plasma compartments contribute to bicarbonate ion (HCO3-) dehydration at the gills for CO2 excretion in contrast to teleost fishes, in which HCO3- dehydration is restricted to RBCs. We compared CA activity levels, subcellular localization, and presence of plasma CA inhibitors in the blood and gills of 13 chondrichthyans to examine the hypothesis that the dogfish model of CO2 excretion applies broadly to chondrichthyans. In general, blood samples from the 12 other chondrichthyans examined had lower RBC CA activity than teleosts, some extracellular CA activity, and no endogenous plasma CA inhibitor. While type IV-like membrane-associated CA was found in the gills in all four of the chondrichthyans examined, S. suckleyi had three times more CA activity (183±13.2 µmol CO2 min-1 mg protein-1) in the microsomal (membrane) fraction of gills than the other three. In addition, unexpected variation in CA characteristics was observed between chondrichthyan species. Thus, in general, it appears that the pattern of CA distribution in fishes can be generally categorized as either chondrichthyan or teleost models. However, further studies should examine the functional significance of the within-chondrichthyan differences we observed and investigate whether CO2 excretion patterns exist along a continuum or in discrete groups.


Assuntos
Anidrases Carbônicas/metabolismo , Brânquias/enzimologia , Squalus/sangue , Animais , Dióxido de Carbono/metabolismo , Anidrases Carbônicas/sangue , Squalus/metabolismo
6.
Aquat Toxicol ; 216: 105318, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590133

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are among the main contaminants in aquatic environments. PAHs can affect organisms due to their carcinogenic, mutagenic and/or teratogenic characteristics. Depending on the PAHs, concentration, and period of exposure, biological damage can occur leading to histopathologic alterations. This study aimed to evaluate the molecular, biochemical and histological responses of the oyster Crassostrea gasar exposed to pyrene (0.25 and 0.5 µM) and fluorene (0.6 and 1.2 µM), after exposure for 24 and 96 h. Concentrations of both PAHs were quantified in the water and in oyster tissues. Transcript levels of phase I (CYP3475C1, CYP2-like, CYP2AU1 and CYP356A) and phase II (GSTO-like, MGST-like and SULT-like) biotransformation-related genes and the activities of ethoxyresorufin-O-deethylase (EROD), total and microsomal glutathione S-transferase (GST and MGST) were evaluated in the gills. Also, histological changes and localization of mRNA transcripts CYP2AU1 in gills, mantle, and digestive diverticula were evaluated. Both PAHs accumulated in oyster tissues. Pyrene half-life in water was significantly lower than fluorene. Transcript levels of all genes were higher in oysters exposed to of pyrene 0.5 µM (24 h). Only CYP2AU1 gene was up-regulated by fluorene exposure. EROD and MGST activities were higher in oysters exposed to pyrene. Tubular atrophy in the digestive diverticula and an increased number of mucous cells in the mantle were observed in oysters exposed to pyrene. CYP2AU1 transcripts were observed in different tissues of pyrene-exposed oysters. A significant correlation was observed between tubular atrophy and the CYP2AU1 hybridization signal in oysters exposed to pyrene, suggesting the sensibility of the species to this PAH. These results suggest an important role of biotransformation-related genes and enzymes and tissue alterations associated to pyrene metabolism but not fluorene. In addition, it reinforces the role of CYP2AU1 gene in the biotransformation process of PAHs in the gills of C. gasar.


Assuntos
Crassostrea/citologia , Crassostrea/genética , Fluorenos/toxicidade , Pirenos/toxicidade , Animais , Biotransformação/efeitos dos fármacos , Crassostrea/efeitos dos fármacos , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Sistema Digestório/efeitos dos fármacos , Fluorescência , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Poluentes Químicos da Água/toxicidade
7.
Aquat Toxicol ; 216: 105315, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561138

RESUMO

Blooms of cyanobacteria, a common event in eutrophic environments, result in the release of potentially toxic substances into the water. The cyanobacterium Radiocystis fernandoi produces microcystin (MC) and other peptides that may disturb homeostasis. This study evaluated the effect of intraperitoneal injections containing the crude extract (CE) of R. fernandoi strain R28 on the gills and kidneys of neotropical fish, Piaractus mesopotamicus, 3, 6 and 24 h post-injection. CE contained MC-RR, MC-YR and minor other oligopeptides. Plasma ions and the activities of the enzymes PP1 and PP2A, Na+/K+-ATPase (NKA), H+-ATPase (HA) and carbonic anhydrase (CA) were determined and morphological changes in both the gills and kidneys were characterized. Compared to controls, the concentration of Na+ within the plasma of P. mesopotamicus decreased after treatment with CE 3 h post treatment and increased after 24 h; the concentration of K+ decreased after 6 h. The activity of the endogenous PP1 and PP2A was unchanged in the gills and was inhibited in the kidneys 6 h after i.p. injection. In the gills, NKA activity increased after 3 h and decreased 6 h post i.p. exposure. Further, NKA activity did not differ from the controls 24-h post injection. In the kidneys, NKA, HA and CA activities were unaffected by treatment. The mitochondria-rich cell (MRC) density in the gills decreased after 3 h in the filament and 3 and 6 h in the lamellae and was restored to the control levels 24 h post-exposure. Filament epithelial hyperplasia and hypertrophy, lamellar atrophy and rupture of the lamellar epithelium were the most common effects of treatment in the gills. No histopathological changes occurred in the kidneys. This study demonstrates that a single dose of toxic CE from R. fernandoi can cause a transitory ion imbalance in P. mesopotamicus which is related to the changes in MRC levels and NKA activity. Ionic balance was recovered 24 h post i.p. injection, however, morphological changes that occurred in the gills took a longer amount of time to return to normal. To conclude, the effects of components contained within the CE of R. fernandoi may be harmful to P. mesopotamicus. In particular, the recovery of ionic regulation depends on MRC responses and histopathological changes produced by CE may affect gas exchange and other gill functions.


Assuntos
Caraciformes/fisiologia , Misturas Complexas/toxicidade , Cianobactérias/metabolismo , Exposição Ambiental , Osmorregulação , Animais , Caraciformes/sangue , Cloretos/sangue , Creatinina/sangue , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Brânquias/patologia , Íons/sangue , Rim/efeitos dos fármacos , Rim/enzimologia , Rim/patologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Osmorregulação/efeitos dos fármacos , Potássio/sangue , ATPases Translocadoras de Prótons/metabolismo , Sódio/sangue , ATPase Trocadora de Sódio-Potássio/metabolismo , Poluentes Químicos da Água/toxicidade
8.
Fish Physiol Biochem ; 45(4): 1245-1260, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31190261

RESUMO

Anthropogenic use of water systems may cause temperature fluctuations between tributaries and large rivers for which physiological population related-effects on osmoregulatory capacity of Atlantic salmon are not well described. We simulated the downstream route in the case of the River Meuse basin to investigate the impact of a 5 °C temperature shift during smoltification on hypo-osmoregulatory capacities of smolts. Three temperature regimes were tested: control temperature-treatment (T1) without temperature shift, early (T2) or late (T3) temperature shift-treatment. Moreover, fish were subjected to seawater challenge during and after the downstream migration peak time. Two allochtonous strains were used: Loire-Allier (LA) and Cong (CG). Without temperature shift (T1), significant differences between the strains were noticed in the peak date and maximum activity of gill Na+/K+ATPase as well as in plasma sodium and potassium concentrations. For early (T2) and late (T3) temperature shift-treatments, gill Na+/K+ATPase activity, plasma osmolality and ion concentrations were negatively influenced in both strains. After salinity challenge, the highest osmolality was measured in smolts subjected to the temperature shift. Predictably circulating levels of GH and IGF-1 changed over the smolting period but they did not explain the observed modifications in hypo-osmoregulatory abilities whatever the population. The results show a negative impact of a temperature shift on hypo-osmoregulatory capacities of smolts regardless of population differences in smoltification timing under conditions without temperature shift. The resilience of such physiological impact was sustained at least for 1 week, comforting the role of high temperature in influencing the rate of changes occurring during smoltification. Therefore, favouring the downstream migration to help smolts reach the sea faster may mitigate the impact of a rapid temperature increase.


Assuntos
Migração Animal , Osmorregulação , Salmo salar/fisiologia , Temperatura Ambiente , Animais , Proteínas de Peixes/metabolismo , Brânquias/enzimologia , Hormônio do Crescimento/sangue , Fator de Crescimento Insulin-Like I/análise , ATPase Trocadora de Sódio-Potássio/metabolismo , Especificidade da Espécie
9.
PLoS One ; 14(4): e0214236, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30964867

RESUMO

Chlorothalonil is a thiol-reactive antifoulant that disperses widely and has been found in the marine environment. However, there is limited information on the deleterious effects of chlorothalonil in marine mollusks. In this study, we evaluated the effects of chlorothalonil on the gill tissues of the Pacific oyster, Crassostrea gigas and the blue mussel, Mytilus edulis after exposure to different concentrations of chlorothalonil (0.1, 1, and 10 µg L-1) for 96 h. Following exposure to 1 and/or 10 µg L-1 of chlorothalonil, malondialdehyde (MDA) levels significantly increased in the gill tissues of C. gigas and M. edulis compared to that in the control group at 96 h. Similarly, glutathione (GSH) levels were significantly affected in both bivalves after chlorothalonil exposure. The chlorothalonil treatment caused a significant time- and concentration-dependent increase in the activity of enzymes, such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR), in the antioxidant defense system. Furthermore, 10 µg L-1 of chlorothalonil resulted in significant inhibitions in the enzymatic activity of Na+/K+-ATPase and acetylcholinesterase (AChE). These results suggest that chlorothalonil induces potential oxidative stress and changes in osmoregulation and the cholinergic system in bivalve gill tissues. This information will be a useful reference for the potential toxicity of chlorothalonil in marine bivalves.


Assuntos
Acetilcolinesterase/metabolismo , Organismos Aquáticos/enzimologia , Crassostrea/enzimologia , Brânquias/enzimologia , Mytilus edulis/enzimologia , Nitrilos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Antioxidantes/metabolismo , Organismos Aquáticos/efeitos dos fármacos , Crassostrea/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Glutationa/metabolismo , Malondialdeído/metabolismo , Mytilus edulis/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade
10.
Cell Stress Chaperones ; 24(3): 503-515, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30915722

RESUMO

Carbonate alkalinity, salinity, and pH are three important stress factors for aquatic animals in saline-alkaline water. Carbonic anhydrases (CAs) catalyze the reversible reaction of CO2 reported to play an important role in the acid-base regulation in vertebrates. To explore the molecular mechanism of CAs efficacy in shrimp after their transfer into saline-alkaline water, the cDNAs of three CAs (EcCAc, EcCAg, and EcCAb) were cloned from Exopalaemon carinicauda. Sequence analysis showed that EcCAc and EcCAg both possessed a conserved α-CA domain and a proton acceptor site, and EcCAb contained a Pro-CA domain. Tissue expression analysis demonstrated that EcCAc and EcCAg were most abundantly in gills, and EcCAb was highly expressed in muscle. The cumulative mortalities remained below 25% under exposure to pH (pH 6 and pH 9), low salinity (5 ppt), or high carbonate alkalinity (5 and 10 mmol/L) after 72 h of exposure. However, mortalities increased up to 70% under extreme saline-alkaline stress (salinity 5 ppt, carbonate alkalinity 10 mmol/L, and pH 9) after 14 days of exposure. The EcCAc and EcCAg expressions in gills were significantly upregulated during the early period of pH and saline-alkaline stresses, while the EcCAb expressions showed no regular or large changes. The two-way ANOVA found significant interactions between salinity and carbonate alkalinity observed in EcCAc, EcCAg, and EcCAb expressions (p < 0.05). Furthermore, an RNA interference experiment resulted in increased mortality of EcCAc- and EcCAg-silenced prawns under saline-alkaline stress. EcCAc knockdown reduced expressions of Na+/H+ exchanger (EcNHE) and sodium bicarbonate cotransporter (EcNBC), and EcCAg knockdown reduced EcCAc, EcNHE, EcNBC, and V-type H+-ATPase (EcVTP) expressions. These results suggest EcCAc and EcCAg as important modulators in response to pH and saline-alkaline stresses in E. carinicauda.


Assuntos
Carbonatos/metabolismo , Anidrases Carbônicas , Brânquias/enzimologia , Palaemonidae/enzimologia , Animais , Anidrases Carbônicas/química , Anidrases Carbônicas/genética , Clonagem Molecular , Expressão Gênica , Concentração de Íons de Hidrogênio , Salinidade , Estresse Fisiológico
11.
Ecotoxicol Environ Saf ; 176: 178-185, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30927639

RESUMO

Diarrhetic shellfish poisoning (DSP) toxins are key shellfish toxins that cause diarrhea, vomiting and even tumor. Interestingly, bivalves such as Perna viridis have been reported to exhibit some resistances to alleviate toxic effects of DSP toxins in a species-specific manner. Nevertheless, the molecular mechanisms underlying the resistance phenomenon to DSP toxins, particularly the mechanistic role of CYP450 is scant despite its crucial role in detoxification. Here, we exposed P. viridis to Prorocentrum lima and examined the expression pattern of the CYP450 and our comprehensive analyses revealed that P. lima exposure resulted in unique expression pattern of key CYP450 genes in bivalves. Exposure to P. lima (2 × 105 cells/L) dramatically orchestrated the relative expression of CYP450 genes. CYP2D14-like mRNA was significantly down-regulated at 6 h in gill, but up-regulated at 2 h in digestive gland compared with control counterparts (p < 0.05), while CYP3A4 mRNA was increased at 12 h in gill. After exposure to P. lima at 2 × 106 cells/L, the expression of CYP3A4 mRNA was significantly increased in digestive gland at 2 h and 12 h, while CYP2D14-like was up-regulated at 6 h. Besides, CYP3L3 and CYP2C8 also exhibited differential expression. These data suggested that CYP3A4, CYP2D14-like, and even CYP3L3 and CYP2C8 might be involved in DSP toxins metabolism. Besides, provision of ketoconazole resulted in significant decrement of CYP3A4 in digestive gland at 2 h and 12 h, while the OA content significantly decreased at 2 h and 6 h compared to control group without ketoconazole. These findings indicated that ketoconazole could depress CYP3A4 activity in bivalves thereby altering the metabolic activities of DSP toxins in bivalves, and also provided novel insights into the mechanistic role of CYP3A4 on DSP toxins metabolism in bivalves.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Dinoflagelados/metabolismo , Toxinas Marinhas/toxicidade , Perna (Organismo)/enzimologia , Intoxicação por Frutos do Mar , Poluentes da Água/toxicidade , Animais , Sistema Enzimático do Citocromo P-450/genética , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Perna (Organismo)/efeitos dos fármacos , Alimentos Marinhos/análise
12.
Aquat Toxicol ; 211: 1-10, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30901626

RESUMO

Flowback and produced water (FPW) is a complex, often brackish, solution formed during the process of hydraulic fracturing. Despite recent findings on the short-term toxicity of FPW on aquatic biota, longer-term impacts of FPW on fish have not yet been investigated and the mechanisms of chronic effects remain unknown. The aim of the present study was to observe the effect of a diluted FPW on ionoregulatory endpoints in the rainbow trout Oncorhynchus mykiss, following a 28-d sub-chronic exposure. A salinity-matched control solution (SW), recreating the salt content of the FPW, was used to differentiate the specific effect of the salts from the effects of the other FPW components (i.e. organics and metals). Overall, fish ionoregulation was not impacted by the chronic exposure. An accumulation of strontium (Sr) and bromide (Br) occurred in the plasma of the FPW-exposed fish only, however no change of plasma ions (Na, K, Cl, Ca, Mg) was observed in SW- or FPW-exposed fish. Similarly, exposures did not alter branchial activity of the osmoregulatory enzymes sodium/potassium ATPase and proton ATPase. Finally, FPW exposure resulted in modifications of gill morphology over time, with fish exposed to the fluid displaying shorter lamellae and increased interlamellar-cell mass. However, these effects were not distinct from morphological changes that also occurred in the gills of control groups.


Assuntos
Monitoramento Ambiental/métodos , Brânquias/efeitos dos fármacos , Fraturamento Hidráulico , Oncorhynchus mykiss/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Cloretos/sangue , Brânquias/enzimologia , Brânquias/patologia , Modelos Teóricos , Oncorhynchus mykiss/sangue , Osmose , Sódio/sangue , ATPase Trocadora de Sódio-Potássio/metabolismo , Testes de Toxicidade Aguda , Testes de Toxicidade Subcrônica
13.
Environ Toxicol Pharmacol ; 67: 61-65, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30716677

RESUMO

The induction of CYP1A activity (EROD) and protein expression was compared in liver and gills of rainbow trout from a stream polluted with crude oil, and through laboratory exposures to 1% and 5% of water accommodated fraction of the crude oil (WAF) for 1 and 4 days. Gills EROD increased 1.6-2.7-fold in fish from the polluted stream and during experiments, while liver EROD was induced only by 1% WAF at day 1 (1.5-fold). Contrastingly, crude oil pollution strongly induced both liver and gills CYP1A protein expression in the field (14-36-fold) and in experiments (4-25-fold). This highlights that crude oil induced CYP1A activity markedly in gills but only slightly or not at all in the liver, suggesting that differences between organ EROD activities are related to the modulation of CYP1A enzyme activity but not to the regulation at transcriptional or translational levels.


Assuntos
Citocromo P-450 CYP1A1/metabolismo , Proteínas de Peixes/metabolismo , Brânquias/efeitos dos fármacos , Fígado/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Água Doce , Brânquias/enzimologia , Fígado/enzimologia , Oncorhynchus mykiss , Poluição por Petróleo/efeitos adversos
14.
Arch Environ Contam Toxicol ; 76(3): 469-482, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30607445

RESUMO

The present study delineate the various biochemical and histopathological tool to evaluate as strong biomarker in the field condition for detection of the least and maximize level of pollution and contamination. We have collected Labeo rohita from 13 different sites from East Kolkata wetland to determine biochemical and histopathological status to analyse metal contamination in the significant biological hot spot EKW. The biochemical marker as antioxidative status, i.e., catalase, superoxide dismutase (SOD), and glutathione-S-transferase (GST) in liver and gill, were remarkably higher (p < 0.01) at some of the sampling sites, but catalase in brain, SOD in kidney, GST in brain and kidney, and neurotransmitter as acetylcholine esterase (AChE) in brain were not significant (p > 0.05) among the sampling sites. The glycolytic enzymes, such as lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in liver, gill, and muscle, and protein metabolic enzymes, such as alanine amino transferase (ALT) and aspartate amino transferase (AST) in liver, gill, muscle, and kidney, were noticeably higher (p < 0.01) at some of the sampling sites. The histopathology of the liver and gill were altered at different sampling sites, such as blood congestion, leucocyte infiltration with parenchymal vacuolisation, nucleus with blood vessels, hepatocytes granular degeneration, haemorrhage, karyorrhexis, shrink nucleus, and pyknotic nuclei in liver. In the gill, structural changes, such as complete destruction and shortening of secondary gill lamellae, blood vessel in gill arch, curling of secondary gill lamellae, aneurism in gill lamellae, and neoplasia, were observed. Most of the metals were found within the safe limit all along the 13 sampling sites, indicating that fishes are safe for the consumption. Based on our finding, we could recommend that a rational application of biochemical profiles, such as oxidative and metabolic stress parameters, including histopathology to be used as biomarkers for biomonitoring the metal contamination in the aquatic environment.


Assuntos
Monitoramento Ambiental/métodos , Peixes/metabolismo , Metais/análise , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/análise , Áreas Alagadas , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Brânquias/enzimologia , Brânquias/patologia , Índia , Fígado/enzimologia , Fígado/patologia , Estresse Fisiológico/efeitos dos fármacos
15.
Artigo em Inglês | MEDLINE | ID: mdl-30315923

RESUMO

Exposure to aluminum (Al) and aluminum + manganese (Mn) can trigger an increase in reactive oxygen species (ROS) and modify the activity of oxidative defense enzymes. This study investigated whether exposure to Al and Al + Mn at acid pH for 24 and 96 h causes oxidative stress evidenced by antioxidants and oxidative damage in the gills and liver of sexually mature Astyanax altiparanae males. The fish were subsequently immersed in metal-free water for 24 and 96 h to see whether they recovered from the effects of these metals. Exposure to an acid pH boosted the activity of gill superoxide dismutase (SOD) at 96 h and the fish did not recover when immersed for the same period in water at neutral pH. Exposure to Al increased glutathione (GSH) levels (24 h) in the gills, returning to control levels during the recovery period, showing the efficiency of the antioxidant system in preventing lipid peroxidation of the gills and liver. Mn did not modify the activity of the enzymes studied, but did trigger late hepatic lipid peroxidation during the recovery period. The group exposed to Al + Mn exhibited several alterations, including increased concentration of GSH, as well as higher GPx and GR activity in the gills. Despite the defensive responses triggered by acute exposure, during the recovery period there were alterations in catalase (96 h) and an increase in hepatic metallothionein (24 h), but this did not prevent hepatic lipid peroxidation. Al and Al + Mn produced different effects, and the timing of enzymatic and non-enzymatic antioxidant defenses also differed.


Assuntos
Alumínio/toxicidade , Characidae/fisiologia , Brânquias/efeitos dos fármacos , Fígado/efeitos dos fármacos , Manganês/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluição Química da Água/efeitos adversos , Adaptação Fisiológica , Animais , Catalase/metabolismo , Sinergismo Farmacológico , Proteínas de Peixes/agonistas , Proteínas de Peixes/metabolismo , Brânquias/enzimologia , Brânquias/metabolismo , Glutationa/agonistas , Glutationa/metabolismo , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Metalotioneína/metabolismo , Reprodutibilidade dos Testes , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo , Testes de Toxicidade Aguda
16.
Artigo em Inglês | MEDLINE | ID: mdl-30267892

RESUMO

We provide a kinetic characterization of (Na+, K+)-ATPase activity in a posterior gill microsomal fraction from a hololimnetic population of the diadromous Amazon River shrimp Macrobrachium amazonicum. Sucrose density gradient centrifugation reveals two distinct membrane fractions showing considerable (Na+, K+)ATP-ase activity, but also containing other microsomal ATPases. Only a single immune-reactive (Na+, K+)-ATPase with Mr of ≈110 kDa is present that hydrolyzes ATP with VM = 130.3 ±â€¯4.8 nmol Pi min-1 mg protein-1 and K0.5 = 0.065 ±â€¯0.00162 mmol L-1, exhibiting site-site interactions. Stimulation by Na+ (VM = 127.5 ±â€¯5.3 nmol Pi min-1 mg protein-1, K0.5 = 5.3 ±â€¯0.42 mmol L-1), Mg2+ (VM = 130.6 ±â€¯6.8 nmol Pi min-1 mg protein-1, K0.5 = 0.33 ±â€¯0.042 mmol L-1), K+ (VM = 126.7 ±â€¯7.7 nmol Pi min-1 mg protein-1, K0.5 = 0.65 ±â€¯0.0079 mmol L-1) and NH4+ (VM = 134.5 ±â€¯8.6 nmol Pi min-1 mg protein-1, K0.5 = 1.28 ±â€¯0.44 mmol L-1) also obeys cooperative kinetics. Ouabain (KI = 0.18 ±â€¯0.058 mmol L-1) inhibits total ATPase activity by ≈70%. This study reveals considerable differences in the kinetic characteristics of the gill (Na+, K+)-ATPase in a hololimnetic population that appear to result from the adaptation of diadromous Macrobrachium amazonicum populations to different limnic habitats.


Assuntos
Proteínas de Artrópodes/metabolismo , Microssomos/enzimologia , Palaemonidae/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Proteínas de Artrópodes/antagonistas & inibidores , Biocatálise , Brasil , Inibidores Enzimáticos/farmacologia , Brânquias/enzimologia , Brânquias/crescimento & desenvolvimento , Brânquias/fisiologia , Microssomos/efeitos dos fármacos , Ouabaína/farmacologia , Palaemonidae/citologia , Palaemonidae/crescimento & desenvolvimento , Palaemonidae/fisiologia , Rios , Tolerância ao Sal , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores
17.
Aquat Toxicol ; 207: 72-82, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30530206

RESUMO

Waterborne ammonia is an environmental pollutant that is toxic to all aquatic animals. However, ammonia induced toxicity as well as compensatory mechanisms to defend against high environmental ammonia (HEA) are not well documented at present for largemouth bass (Micropterus salmoides), a high value fish for culture and sport fisheries in the United States. To provide primary information on the sensitivity of this species to ammonia toxicity, a 96 h-LC50 test was conducted. Thereafter, responses at physiological, ion-regulatory and transcript levels were determined to get insights into the underlying adaptive strategies to ammonia toxicity. For this purpose, fish were progressively exposed to HEA (8.31 mg/L representing 25% of 96 h-LC50) for 3, 7, 14, 21 and 28 days. Temporal effects of HEA on oxygen consumption rate (MO2), ammonia and urea dynamics, plasma ions (Na+, Cl- and K+), branchial Na+/K+-ATPase (NKA) and H+-ATPase activity, muscle water content (MWC), energy store (glycogen, lipid and protein) as well as branchial mRNA expression of Rhesus (Rh) glycoproteins were assessed. Probit analysis showed that 96 h-LC50 of (total) ammonia (as NH4HCO3) at 25 °C and pH 7.8 was 33.24 mg/L. Results from sub-lethal end-points shows that ammonia excretion rate (Jamm) was strongly inhibited after 7 days of HEA, but was unaffected at 3, 14 and 21 days. At 28 days fish were able to increase Jamm efficiently and concurrently, plasma ammonia re-established to the basal level. Urea production was increased as evidenced by a considerable elevation of plasma urea, but urea excretion rate remained unaltered. Expression of Rhcg isoform (Rhcg2) mRNA was up-regulated in parallel with restored or increased Jamm, suggesting its ammonia excreting role in largemouth bass. Exposure to HEA also displayed pronounced augmentations in NKA activity, exemplified by a rise in plasma [Na+]. Furthermore, [K+], [Cl-] and MWC homeostasis were disrupted followed by recovery to the control levels. H+-ATPase activity was elevated but NKA did not appear to function preferentially as a Na+/NH4+-ATPase. From 14 days onwards MO2 was depressed, potentially an attempt towards minimizing catabolism. Glycogen content in liver and muscle were temporarily depleted, whereas a remarkable increment in protein was evident at the last exposure period. Overall, these data suggest that ammonia induced toxicity can disturb several biological processes in largemouth bass, however, it can adapt to the long-term sub-lethal ammonia concentrations by activating various components of ammonia excretory, ion-regulatory and metabolic pathways.


Assuntos
Amônia/toxicidade , Bass/fisiologia , Exposição Ambiental/análise , Adenosina Trifosfatases/metabolismo , Animais , Bass/genética , Perfilação da Expressão Gênica , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Glicoproteínas/metabolismo , Íons/sangue , Metaboloma , Músculos/metabolismo , Nitrogênio/metabolismo , Análise de Componente Principal , ATPases Translocadoras de Prótons/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Análise de Sobrevida , Fatores de Tempo , Ureia/metabolismo , Poluentes Químicos da Água/toxicidade
18.
Artigo em Inglês | MEDLINE | ID: mdl-30389628

RESUMO

Fathead minnows, Pimephales promelas, are found throughout the continental United States in waters in which salinity can change with tides and temperatures vary seasonally. They have been used extensively in studies of environmental toxicology and are commercially important. In a very recent study in our labs RNA Seq was used to assemble transcriptomes from the gills of fatheads acclimated to either 5° or 22 °C. By comparison with published genomes, transcripts were identified for a number of ion transporters, ion channels, and signal molecule receptors, as well as enzymes that generate ammonia. H-ATPase and Na/K-ATPase activities were measured in supernatants of gill homogenates from fish acclimated to water sodium concentrations of 1.6, 3.1 or 124 mM sodium. As the water sodium concentration increased, in vitro activities of Na/K-ATPase activity and gill glutamate dehydrogenase activity decreased while H-ATPase activity increased. In a second series of experiments minnows were acclimated to 5 °C, 12.5 °C or 22 °C. In vitro activity of Na/K-ATPase decreased but activities of H-ATPase and glutamate dehydrogenase increased as temperature increased in gill membranes. These data do not support a primary role for apical H-ATPase in sodium influx under all conditions but do suggest a role for glutamate dehydrogenase production of ammonium to act as a counter-ion for sodium uptake by NHE-3.


Assuntos
Cyprinidae/metabolismo , Brânquias/enzimologia , Glutamato Desidrogenase/metabolismo , Salinidade , ATPase Trocadora de Sódio-Potássio/metabolismo , Temperatura Ambiente , Aclimatação , Animais , Cyprinidae/fisiologia , Transporte de Íons , Sódio/metabolismo , Transcriptoma
19.
Artigo em Inglês | MEDLINE | ID: mdl-30594527

RESUMO

The cell cycle comprises a series of steps necessary for cell growth until cell division. The participation of proteins responsible for cell cycle regulation, known as cyclin dependent kinases or Cdks, is necessary for cycle progression. Cyclin dependent kinase 2 (Cdk-2) is one of the most studied Cdks. This kinase regulates the passage through the G1/S phase and is involved in DNA replication in the S phase. Cdks have been extensively studied in mammals, but there is little information about these proteins in crustaceans. In the present work, the nucleotide and amino acid sequence of Cdk-2 from the white shrimp (Cdk-2) and its expression during hypoxia and reoxygenation are reported. Cdk-2 is a highly conserved protein and contains the serine/threonine catalytic domain, an ATP binding site and the PSTAIRE sequence. The predicted Cdk-2 structure showed the two-lobed structure characteristic of kinases. Expression of Cdk-2 was detected in hepatopancreas, gills and muscle, with hepatopancreas having the highest expression during normoxic conditions. Cdk-2 expression was significantly induced after hypoxia for 24 h in muscle cells, but in hypoxia exposure for 24 followed by 1 h of reoxygenation, the expression levels returned to the levels found in normoxic conditions, suggesting induction of cell cycle progression in muscular cells during hypoxia. No significant changes in expression of Cdk-2 were detected in these conditions in hepatopancreas and gills.


Assuntos
Proteínas de Artrópodes/metabolismo , Quinase 2 Dependente de Ciclina/metabolismo , Hipóxia/enzimologia , Oxigênio/metabolismo , Penaeidae/enzimologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Sequência de Bases , Quinase 2 Dependente de Ciclina/química , Quinase 2 Dependente de Ciclina/genética , Brânquias/enzimologia , Hepatopâncreas/enzimologia , Músculos/enzimologia , Penaeidae/metabolismo , Filogenia
20.
Biol Trace Elem Res ; 187(2): 526-535, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29948908

RESUMO

Gobionellus oceanicus is a species widely distributed on the Atlantic coast and may be susceptible to anthropic effects. This study evaluated the morphology and the Na+/K+-ATPase activity of G. oceanicus gills considering the concentration of metals in the fish and Subaé River estuary. Although the metal concentrations detected in the water and sediment did not exceed certain limits, CONAMA (Brazilian Environment Council), TEL (Threshold Effect Level), and PEL (Probable Effect Level), the metals levels in gills plus muscle and skin of G. oceanicus were above the permitted setting of the Ministry of Health, Brazil. The pavement epithelial cells (PVC) of the gill filament was observed that there were long microridges either in the apical surface or in the lamella; especially, microridges degeneration was shown in some PVC from filament epithelium. The number of ionocyte and the volume density were (0.02 ± 0.001)/µm and (0.38 ± 0.27) %, respectively. The activity of Na+/K+-ATPase was 1.13 ± 0.76 µM Pi mg protein-1 h-1. We describe the volume density and number of ionocytes and Na+/K+-ATPase enzymatic activity in G. oceanicus for the first time, which is useful for basic and comparative future studies to support aquatic biomonitoring.


Assuntos
Estuários , Proteínas de Peixes/metabolismo , Brânquias/enzimologia , Perciformes/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Brasil , Água Doce/química , Geografia , Sedimentos Geológicos/química , Brânquias/anatomia & histologia , Brânquias/metabolismo , Transporte de Íons , Metais/análise , Concentração Osmolar , Perciformes/anatomia & histologia , Água do Mar/química
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