Oxidative metabolism in Odontesthes nigricans Richardson (Pisces, Atherinopsidae) from the Beagle Channel, Argentina.

LATTUCA M, MALANGA G, PÉREZ A, CALVO J, PUNTARULO S

Bahía Blanca

Conferencia; ECSA 44. Science and management of estuaries and coasts; 2008

IADO-Universidad Nacional del Sur

The aim of this work was to study comparatively oxidative metabolism in gills and liver of a silverside, Odontesthes nigricans, in their natural environment. This species can be found, following rising tides, along coastal waters and estuaries of the Beagle Channel in Tierra del Fuego. Fish were collected with seine net at Cambaceres Bay (54°52´S, 67°16´W) in September 2007. Oxidative metabolism at the hydrophilic level was assessed as the ratio ascorbyl radical content (A·)/ascorbate content (AH-). The A·content, measured by EPR, showed no significant differences between gills and liver of fish. HPLC determinations of AH- content were 12±2 (pmol/mg FW) in gills and 159±28 (pmol/mg FW) in liver. The ration A·/AH- was significantly different between organs (6.10-5±2.10-5 and 5.10-6±2.10-6, for gills and liver, respectively). Oxidative damage of lipid was evaluated through TBARS and lipid radical content, being both determinations significantly higher in gills. The assessment of catalase activity and antioxidant lipid soluble content (a-tocopherol and b-carotene) showed significantly higher values for liver than for gills. Taken as a whole, O. nigricans liver exhibited a better antioxidant system than gills, allowing minimization of intracellular damage when exposed to environmental stressing conditions.