Ictiotiofauna captured by artisan fishermen in Lagoa Pequena – Estuarine region of Lagoa dos Patos – RS

Through monthly evaluations, the main species of fish captured by the fisherman of Lagoa Pequena, a site in the estuarine region of Lagoa dos Patos – RS, were identified. The biomass data, in addition to the absolute and relative frequencies of each species, were submitted to correlation analysis with the seasons of the year and environmental variables. Although water salinity was found to be constantly above 3.5, there was a predominance of the capture of 85.8% of characteristic freshwater species and 15.5% of estuarine species. The economic values of the species, the types of fishing and the seasons of the year are the main determinants of the local fishing production

Ictiofauna capturada por pescadores artesanais na Lagoa Pequena – Região estuarina da Lagoa dos Patos – RS

Através de avaliações mensais foram identificadas as principais espécies de peixes capturadas por pescadores artesanais que atuam na Lagoa Pequena, localizada na região estuarina da Lagoa dos Patos – RS. Os dados de biomassa, freqüência absoluta e relativa de cada espécie foram submetidas à análise de correlação com a estação do ano e variáveis ambientais. Embora a salinidade tenha se mantido acima de 3,5, houve predominância da captura de 85,5% de espécies características de água doce e 15,5% de espécies estuarinas. O valor econômico das espécies, as artes de pesca e estação do ano são determinantes na produção pesqueira local

Relação do estresse oxidativo no desenvolvimento da hipertrofia cardíaca através da ativação da via de sinalização Akt no hipertireoidismo experimental

41

Relação do estresse oxidativo no desenvolvimento da hipertrofia cardíaca através da ativação da via de sinalização Akt no hipertireoidismo experimental

41

Peripheral markers of oxidative stress in chronic mercuric chloride intoxication

The present study was designed to evaluate the time course changes in peripheral markers of oxidative stress in a chronic HgCl2 intoxication model. Twenty male adult Wistar rats were treated subcutaneously daily for 30 days and divided into two groups of 10 animals each: Hg, which received HgCl2 (0.16 mg kg-1 day-1), and control, receiving the same volume of saline solution. Blood was collected at the first, second and fourth weeks of Hg administration to evaluate lipid peroxidation (LPO), total radical trapping antioxidant potential (TRAP), and superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase (CAT). HgCl2 administration induced a rise (by 26%) in LPO compared to control (143 ± 10 cps/mg hemoglobin) in the second week and no difference was found at the end of the treatment. At that time, GST and GPx were higher (14 and 24%, respectively) in the Hg group, and Cu,Zn-SOD was lower (54%) compared to control. At the end of the treatment, Cu,Zn-SOD and CAT were higher (43 and 10%, respectively) in the Hg group compared to control (4.6 ± 0.3 U/mg protein; 37 ± 0.9 pmol/mg protein, respectively). TRAP was lower (69%) in the first week compared to control (43.8 ± 1.9 mM Trolox). These data provide evidence that HgCl2 administration is accompanied by systemic oxidative damage in the initial phase of the process, which leads to adaptive changes in the antioxidant reserve, thus decreasing the oxidative injury at the end of 30 days of HgCl2 administration. These results suggest that a preventive treatment with antioxidants would help to avoid oxidative damage in subjects with chronic intoxication