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- Oxidative stress response in gill and liver of Liza saliens, from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Ferreira, Marta S.; Salgado, Maria AntóniaTissue-specific responses against oxidative stress and lipid peroxidation were analyzed in wild adult mullet (Liza saliens) caught in the Portuguese coastal lagoon Esmoriz-Paramos. Parameters measured were catalase (CAT), superoxide dismutase (SOD), and glutathione- S-transferase (GST) activities in liver and gill tissues and lipid peroxidation. The enzyme activities were related to gill histopathological alterations, as well as to heavy metals (Cu and Zn) concentrations in these tissues. Gill epithelium of L. saliens showed histological alterations, such as epithelial hyperplasia resulting in lamellar fusion, epithelial lifting, vasodilatation, and lamellar aneurisms, with a prevalence ranging from 62% to 92%. The highest Cu content was found in liver (379 mg kg-1), while the highest Zn content was observed in gill (119 mg kg-1). SOD and CAT activities showed differences between gill and liver. The highest activities found were SOD in gill (10.1 U/mg protein) and CAT in liver (39.2 mmol/min/mg protein). In gill, CAT activity was negatively related to both Cu levels and gill lifting, while a positive relationship was found between SOD activity and fish age. The positive relationship between Cu and CAT activity in liver suggests that an increase in metabolic level is related to Cu-induced oxidative stress. The decrease in gill CAT activity can be due to osmotic stress caused by damaged gill epithelium. CAT activity in liver is an appropriate biomarker of oxidative stress in the Esmoriz-Paramos lagoon.
- Bioaccumulation of metals by Mugil saliens under chronic exposure to contamined sediments: Gill histopathological changesPublication . Fernandes, Conceição; Monteiro, Sandra Mariza; Fontaínhas-Fernandes, A.; Salgado, Maria AntóniaThe Esmoriz/Paramos coastal lagoon, is a habitat of ecological importance due to the presence of unique animal and plant species. During the past few years its immersed area has been gradually reduced due to effluent discharges and siltation. The major contaminants in the lagoon are derived from a multitude of nonpoint sources associated with urbanization and industrial activities within the watershed. Heavy metals are probably a class of pollutants contributing to the observed decline of fish species. The metal content in the water and sediments in the lagoon were investigated as well as gill metal bioaccumulation and gill histopathological changes of the grey leaping mullet, Mugil saliens.
- Can fish adopt the same defence strategy in gill and liver to face chronic metal exposure?Publication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Carrola, João; Salgado, Maria Antónia
- Changes in plasma electrolytes and gill histopathology in wild Liza saliens from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Monteiro, Sandra Mariza; Salgado, Maria AntóniaThe Esmoriz-Paramos is a lagoon of great ecological significance located on the Northwest coast of Portugal. The quality of water and sediment within this ecosystem has been gradually degraded due to the discharges of mostly untreated industrial waste and domestic sewage. Contaminants include heavy metals that can be taken up by fish from water, food, sediments, and suspended particulate material. Fish inhabiting polluted water bodies tend to accumulate many chemicals in high concentrations, even when the environmental contamination levels are low (Colombo et al. 1995). The leaping grey mullet (Liza saliens) is one of a few dominant species living in this environment. This species may contact xenobiotics in the water column or, when feeding, in the sediments.
- Pesquisa de resíduos de fungicidas no mosto e no vinhoPublication . Pinto, Miguel; Pereira, Sandra; Fernandes, Conceição; Andrade, João Verdial; Estevinho, Leticia M.
- Osmotolerância em levedurasPublication . Fernandes, Conceição; Rocha, Amélia; Estevinho, Leticia M.No presente trabalho, seleccionaram-se diferentes estirpes de leveduras para testar a sensibilidade ao cloreto de sódio (NaCI). As estirpes usadas foram Saccharomyces cerevisiae ESAl, Candida utiJis ESA 2L Zygosaccharomyces bailii ISA 1307, Zygosaccharomyces rouxii ESA 18 e Candida pelliculosa ESA 16, tendo sido estimadas a taxa específica de crescimento (Kc) e a produção de biomassa na ausência e na presença de sal.
- Can fish adopt the same defence strategy in gill and liver to face chronic metal exposure?Publication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Carrola, João; Salgado, Maria Antónia
- Heavy metal contamination in a mugil wild population of a coastal lagoonPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Cabral, David; Carrola, João; Salgado, Maria AntóniaPolluted sediments usualy contain complex chemical mistures that may have synergistic and/or antagonistic effects on target organisms. Establishing causality in the 1ieId, is thus, particularly difficulty and the biomarker responses recorded in whole sediment toxicity assays are o correlactive nature only
- Bioaccumulation of heavy metals in Liza saliens from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Peixoto, Francisco P.; Salgado, Maria AntóniaHeavy metal (Cu and Zn) concentrations in liver, gills, and muscle of leaping grey mullet, Liza saliens, from the Portuguese Esmoriz–Paramos coastal lagoon were measured to evaluate their bioaccumulation as a function of sediment contamination. The highest metal concentrations were observed in the liver (254mg Cu kg 1) and gills (114 mgZn kg 1). Bioaccumulation factors (BAFs) were found to follow the order: Cu-liver4Cu-gills4Cu-muscle and Zn-gills4Zn-liver4Zn-muscle. The highest BAFs were observed in the organs mainly implicated in metal metabolism and a significant positive relationship was found between BAFs and fish age. These results suggest the loss of homeostatic capacity of L. saliens under chronic metal exposure leading to bioaccumulation. Furthermore, Cu-liver and Zngills accumulation can be good environmental indicators of metal stress in L. saliens
- Histopathological gill changes in wild leaping grey mullet (Liza saliens) from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Monteiro, Sandra Mariza; Salgado, Maria AntóniaThe histopathological changes are among the most recognized responses to environmental stressors, namely heavy metals. Liza saliens were sampled, in the Portuguese Esmoriz-Paramos coastal lagoon to assess their gill histopathological response to Cu and Zn contaminated sediments. A lesion prevalence index, severity, and extension scores of each lesion, as well as an assessment value (severity extension), were determined to evaluate the effect of environmental heavy metal exposure. The main histopathological changes observed were aneurisms, hyperplasia, lifting, and vasodilation. A high prevalence for each lesion (65–85%) was found, in addition to a high number of simultaneous lesions. Vasodilation and hyperplasia were the lesions that showed higher prevalence indexes. Lifting, followed by hyperplasia, were the lesions with highest assessment value. The prevalence of the number of the lesions found in L. saliens collected from the Esmoriz-Paramos lagoon was high when compared with mullet caught in the sea. A previous work revealed that fish collected in the lagoon showed elevated Cu and Zn levels in their gills, in a positive correlation with age. However, no positive correlation was observed between assessment value and gill metal levels.
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