Oxidative activities, metalothionein levels and lipid oxidation in perisheral blood in Otaria flavescens (Southamerican Sea Lion)

POLIZZI, PAULA; ANSALDO, MARTÍN; VALERIA RUOPPOLO; RODRIGUEZ, DIEGO; PONCE DE LEÓN, ALBERTO; GERPE, MARCELA

California

Congreso; PRIMO 16 Pollutant Responses in Marine Organisms; 2011

Otaria flavescens inhabits Atlantic and Pacific coasts of South America, being frequent at Uruguay-Argentina coast. Samples of marine mammals in good condition to allow the assessment of biomarkers are really difficult. Therefore, noninvasive sampling could be a good way to obtain environmental stress information. The aim was to determine oxidative enzyme activities (superoxide dismutase, cabalase, glutathion peroxidase and glutathion-S-transferase), lipid oxidation (TBARS), protein oxidation and metallothionein (MT) in erythrocytes of female sea lions. Samples were obtained from a reproductive colony (Isla de Lobos, Uruguay, 35º01’38”S-54º52’55”W) during May 2010. Fifteen females -adult and subadult, good health, maintained under standard conditions of rest) were analyzed. Blood samples were from the interdigital vein of pectoral fin. Erythrocytes fraction was obtained, immediately frozen in liquid nitrogen and kept at -80ºC. Determinations were performed by UV-Vis spectroscopy. MT levels in subadult females were higher than those of adults. The maximum TBARS concentrations were showed in subadult sea lions. By other way, maximum levels of CAT were registered in adults. The other enzymes did not present significant variation among sea lions. Furthermore, respirometry assessments showed no differences in oxygen consumption (indicator of metabolic rate by breath) among individuals at rest status. These results suggest that levels of oxidative enzyme activities correspond to low production states of reactive oxygen species (ROS), unlike to would expect at evaluation performed immediately after dive periods. Results are first information related to oxidative stress in Otaria flavescens, and establish the basis for future assessments through noninvasive analyses. It is highlighted the valuable obtained information that could be use in the protection and conservation of the species.