Repository logo
 
Loading...
Profile Picture
Person

Pereira Serafim, Maria Angela

Search Results

Now showing 1 - 10 of 28
  • Effect of different hydrothermal vent conditions in the proteome of vent mussel Bathymodiolus azoricus
    Publication . Company, Rui; Serafim, A.; Bebianno, Maria João; Cajaraville, M.; Antúnez, O.; Torreblanca, A.
    The mytilid mussel Bathymodiolus azoricus is the most representative species of north Mid Atlantic Ridge (MAR) hydrothermal vents and is abundantly found at Menez-Gwen, Lucky Strike and Rainbow vent sites.
  • Metallothioneins in the clam Ruditapes decussatus: an overview
    Publication . Bebianno, Maria João; Serafim, MA; Simes, Dina
    The clam Ruditapes decussatus is a suspension-feeding bivalve mollusc widely distributed in European waters and in the Mediterranean. Due to is economic importance it is heavily harvested in many countries, and particularly in Portugal. Its ability to accumulate high metal concentrations along with its economic importance was the main reason for its selection as a bioindicator. Metallothionein (MT) concentrations in the clams R. decussatus followed by gel filtration chromatography, differential pulse polarography and SDS-PAGE, after Cd exposure, revealed that MT is induced in different tissues (whole soft tissues, gills, digestive gland and remaining tissues) but the level of MT induction is tissue dependent. MT from the gills and the digestive gland give a more sensitive response to assess the effects of metal exposure directly from the water or from the food than in the whole soft tissues. MT levels were also measured in the gills, digestive gland and remaining tissues of R. decussatus collected in the Ria Formosa lagoon (Portugal) from areas of different metal load and during the period of sexual differentiation of the clam. Data revealed that there were significant differences of MT concentrations among sites and season but not among sex. Purification of MT from the digestive gland of R. decussatus revealed four MT isoforms. The molecular weight of one of these isoforms, determined by SDS-PAGE, was of the same order of magnitude as that of MT from other bivalve species. Similarly the amino acid sequence of the beta domain of the MT of the digestive gland of the clam also shows some degree of similarity with the similar MT sequence from mussels and oysters. It is, therefore suggested that there is some degree of similarity in the MT structure among these species.
  • DNA damage and lipid peroxidation vs. protection responses in the gill of Dicentrarchus labrax L. from a contaminated coastal lagoon (Ria de Aveiro, Portugal)
    Publication . Ahmad, I.; Maria, Vera L.; Oliveira, M.; Serafim, Angela; Bebianno, Maria João; Pacheco, M.; Santos, M.A.
    The present research work aimed to investigate the damage vs. protection responses in gill of European sea bass (Dicentrarchus labrax) captured at a polluted coastal lagoon, Ria de Aveiro (Portugal), as a tool to evaluate the human impacts on environmental health. Damage was assessed as DNA strand breakage and lipid peroxidation (LPO) whereas protection was evaluated by measuring catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), total glutathione (GSHt), thiols and metallothioneins (MT). Fish were caught at five locations: Gafanha (GAF), Rio Novo do Príncipe (RIO), Laranjo (LAR) and Vagos (VAG) presenting each a different recognized source of contamination, and Torreira (TOR), assumed as reference site. Among the surveyed sites, gill damage was observed only at GAF, as measured by DNA integrity loss and LPO increase. An overall induction in enzymatic antioxidant protection was perceptible in fish from GAF and VAG, expressed as higher GPX, GR and GST activities. In addition, LAR fish showed elevated GST and CAT activities. Thiols content was higher in all study sites irrespective to the pollution spectrum, whereas GSHt increase was only observed at GAF and VAG. The highest MT level was detected in fish from VAG and the lowest level from RIO suggesting a low contamination degree on this particular site. Globally, the results expressed site-specific response patterns, signalling two critical areas - GAF and VAG. Additionally, a joint analysis (damage vs. protection) allowed the following ordering of surveyed sites according to the contamination degree and risk to fish health; GAF>VAG>LAR>RIO>TOR. D. labrax gill responses demonstrated their efficacy as early warning signals of the contaminants presence. Moreover, the adopted approach, considering simultaneously protection responses and damaging effects, also revealed its usefulness on the pollution extent assessment.
  • Wild juvenile Dicentrarchus labrax L. liver antioxidant and damage responses at Aveiro Lagoon, Portugal
    Publication . Maria, Vera L.; Ahmad, I.; Oliveira, M.; Serafim, Angela; Bebianno, Maria João; Pacheco, M.; Santos, M. A.
    The Aveiro Lagoon, at the north-western coast of Portugal, has been under considerable anthropogenic pressure for the last 5 decades. In order to perform an adequate survey of the effects induced by the contaminants in presence, wild juveniles Dicentrarchus labrax (sea bass) were selected. Thus, sea bass was captured at five sites: Torreira (TOR, as reference site), Gafanha (GAF), Rio Novo Príncipe (RIO), Laranjo (LAR) and Vagos (VAG) in autumn 2005. Liver defence responses such as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), total glutathione (GSHt), total non-protein thiols (NP-SH) and metallothioneins (MT) were measured. Liver damage was determined as lipid peroxidation (LPO) and DNA integrity loss. RIO, LAR and VAG presented lower CAT, GR, GST activities and NP-SH and GSHt depletion in comparison to TOR. VAG and LAR showed higher GPx activity when compared to TOR. The highest MT level was found at GAF and VAG. The NP-SH and DNA integrity decreased at GAF compared to TOR. This field study demonstrated that not only antioxidant induction but also inhibitory responses must be considered as a signal of contamination.
  • Temporal variation in the antioxidant defence system and lipid peroxidation in the gills and mantle of hydrothermal vent mussel Bathymodiolus azoricus
    Publication . Company, Rui; Serafim, Angela; Cosson, Richard; Fiala-Médioni, Aline; Dixon, David; Bebianno, Maria João
    Hydrothermal vent mussels are exposed continually to toxic compounds, including high metal concentrations and other substances like dissolved sulphide, methane and natural radioactivity. Fluctuations in these parameters appear to be common because of the characteristic instability of the hydrothermal environment. Temporal variation in the antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidases (Total GPx), selenium dependent glutathione peroxidases (Se-GPx)), metallothioneins and lipid peroxidation (LPO) in the gills and mantle of the mussel Bathymodiolus azoricus from Menez-Gwen hydrothermal vent site was evaluated and related to the accumulated metal concentrations (Ag, Cu, Cd, Fe, Mn and Zn) in the tissues. Maximum antioxidant enzyme activities in the gills were detected in the beginning of summer, followed by a gradual decrease throughout the following months. One year after, the levels of antioxidant enzyme activities were similar to those reported one year before. LPO in this tissue exhibited a similar temporal variation trend. A different pattern of temporal variation in antioxidant enzyme activities was observed in the mantle, with a gradual increase from summer to the end of autumn (November). LPO in the mantle exhibited an almost reverse trend of temporal variation to that of antioxidant enzyme activities in this tissue. Antioxidant defences in the gills of B. azoricus were significantly enhanced with increasing concentrations of Ag, Cu and Mn, while negative relationships between antioxidant enzymes and Cd, Cu, Mn and Zn concentrations in the mantle were observed, suggesting different pathways of reactive oxygen species (ROS) production and that these tissues responded differently to the metal accumulation. However, temporal variation in biomarkers of defence and damage were in general similar to coastal bivalve species and can be associated with temporal variations of the physiological status due to reproduction. These variations might also be linked to the highly unstable nature of the hydrothermal environment. (c) 2006 Elsevier Ltd. All rights reserved.
  • Comparative petroleum hydrocarbons levels and biochemical responses in mussels from hydrothermal vents (Bathymodiolus azoricus) and coastal environments (Mytilus galloprovincialis)
    Publication . Serafim, Angela; Lopes, Belisandra; Company, Rui; Ferreira, A. M.; Bebianno, Maria João
    Aliphatic hydrocarbons and PAHs in the whole soft tissues of Bathymodiolus azoricus from three Mid-Atlantic Ridge hydrothermal vents (Menez-Gwen, Lucky Strike and Rainbow), and Mytilus galloprovincialis from three contaminated coastal sites in South Portugal were analysed, and its effects on the digestive gland microsomes mixed-function oxygenase system (MFO) were assessed. Aliphatic hydrocarbons levels were present in the same magnitude in both coastal and hydrothermal environments, while the UCM (unresolved complex mixture) for coastal mussels were higher than in vent mussels. In general, significantly higher PAHs concentrations were found in coastal mussels, compared to B. azoricus where low molecular weight PAHs (2-3 rings) represented the majority of PAHs contrarily to what was observed in M. galloprovincialis. The MFO components were present in both mussel species, and were detected in vent mussels for the first time. However this system seems to have different roles in species from these contrasting environments. In coastal mussels MFO responded to hydrocarbon contamination while response in hydrothermal organisms appeared to be related mainly to endogenous factors.
  • Induction of cadmium-binding peptides in sorghum
    Publication . Pinto, Ana Paula Honrado; Serafim, Angela; Bebianno, Maria; Almeida Mota, Ana Maria
    Hydroponic experiments with sorghum were carried out in nutrient solution medium, under controlled environmental conditions for different periods of time. Cadmium (Cd ) was added at a final concentration of 0.1, 1 and 10 mg dm−3. The effect of time and cadmium concentration on the content of thiolic groups (TSH) in the “cell sap” of sorghum tissues are discussed in relation to plant resistance/tolerance to metal stress. The increase in Cd level in the nutrient solution was associated with a higher total Cd accumulation in the plant (root and shoot), which produced a significant enhancement on the thiolic groups content. Furthermore, higher Cd concentrations in plant tissues induced not only an increase in sulphur-rich compounds but also enhanced the binding capacity of these compounds.
  • A multibiomarker approach in Mytilus galloprovincialis to assess environmental quality
    Publication . Cravo, Alexandra; Lopes, Belisandra; Serafim, M.A.; Company, Rui; Barreira, Luísa; Gomes, Tânia; Bebianno, Maria João
    A multibiomarker approach was carried out for the first time in the South Portuguese Coast using Mytilus galloprovincialis, to assess environmental quality, establish if there are adverse biological responses associated to different sources of anthropogenic contamination and to determine spatial and seasonal trends. For this purpose the battery of biomarkers selected was: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx total and Se dependent), Cytochrome P450 component system, Glutathione-S-transferase (GST) and acetylcholinesterase (AChE), metallothionein (MT) and lead-delta-aminolevulinic acid dehydratase (ALAD), lipid peroxidation (LPO) and Condition Index (CI) along with the determination of PAHs and metals (Cd, Cu, Ni, Pb and Zn). Results show that despite the levels of both organic and metallic contaminants in these eight spots in the South Coast of Portugal not being particularly high compared with other contaminated/polluted sites worldwide, the selected battery of biomarkers responded efficiently to the environmental changes and allowed an environmental assessment between seasons and sites. Different spatial and seasonal responses were evident along the South Coast of Portugal, meaning that the contamination is not homogeneous. This does not only reflect different competition, origin and intensity of contamination, but also different environmental conditions (e.g. temperature, salinity). Along the South Portuguese Coast site 8 was the most contaminated, while site 2 was considered the least contaminated. Despite environmental factors possibly causing difficulties in the general interpretation of biomarker data, those that better responded to environmental contamination were CYP450, SOD-mit and T-GPx for the summation SigmaPAHs, MT (digestive gland) for metals (especially Cu), ALAD for Pb and LPO for both organic and metallic contamination. These biomarkers were also positively correlated with temperature in summer, revealing this as a more stressful/critical season. In future environmental contamination assessments there is no need to analyse the components b5, P418, NADH and NADPH of phase I MFO system, and MT in the gills, since their responses are not evident.
  • Response of antioxidant systems to copper in the gills of the clam Ruditapes decussatus
    Publication . Geret, Florence; Serafim, Angela; Barreira, Luísa; Bebianno, Maria João
    Copper (Cu) is an essential element for biological systems, however, when present in excess, is toxic. Metallothioneins can play an important role in Cu homeostasis and detoxification. Moreover, Cu can catalyse the production of toxic hydroxyl radicals that cause lipid peroxidation but defence systems in the cells can limit the oxidative damage. The present study was performed to investigate the effect of three Cu concentrations (0.5, 2.5 and 25 mug l(-1)) on the response of antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), selenium-dependent glutathion peroxidase and total glutathion peroxidase), total proteins, metallothioneins (MT), malondialdehyde (MDA) concentrations in the gills of the clam, Ruditapes decussatus. The activity of antioxidant enzymes and total proteins, MT and MDA concentrations were measured in the gills of the clams after 1, 3, 7, 14, 21 and 28 days of Cu exposure. Results indicate that Cu only induces an imbalance in the oxygen metabolism during the first week of Cu exposure due to a decrease in mitochondrial SOD and CAT, selenium-dependent and total glutathion peroxidase activities. Cu also causes lipid peroxidation, measured by the MDA formation, that was Cu dependent. In the gills of clams exposed to 25 mug Cu/l, the excess of Cu triggers the induction of MT synthesis after 3 days. of exposure.
  • Effect of cadmium, copper and mercury on antioxidant enzyme activities and lipid peroxidation in the gills of the hydrothermal vent mussel Bathymodiolus azoricus
    Publication . Company, Rui; Serafim, Angela; Bebianno, Maria João; Cosson, R.; Shillito, B.; Fiala-Médioni, A.
    Metals are known to influence lipid peroxidation and oxidative status of marine organisms. Hydrothermal vent mussels Bathymodiolus azoricus live in deep-sea environments with anomalous conditions, including high metal concentrations. Although B. azoricus are aerobic organisms they possess abundant methano and thioautotrophic symbiotic bacteria in the gills. The enzymatic defences (superoxide dismutase (SOD), catalase (CAT), total glutathione peroxidase (Total GPx) and selenium-dependent glutathione peroxidase (Se-GPx)) and lipid peroxidation were determined in the gills of B. azoricus exposed to Cd (0.9 microM), Cu (0.4 microM) and Hg (0.1 microM) with different times of exposure. The experiments were performed in pressurized containers at 9+/-1 degrees C and 85 bars. Results show that vent mussels possess antioxidant enzymatic protection in the gills. Cd and Cu had an inhibitory effect in the enzymatic defence system, contrarily to Hg. These enzymatic systems are not completely understood in the B. azoricus, since reactive oxygen species might be produced through other processes than natural redox cycling, due to hydrogen sulphide and oxygen content present. Also the symbiotic bacteria may play an important contribution in the antioxidant protection of the gills.