Heart oxidative metabolism after exposure to ambient particles

MARCHINI, TIMOTEO; MAGNANI, NATALIA; TASAT, DEBORAH; ALVAREZ, SILVIA; EVELSON, PABLO

Santiago de Chile, Chile

Congreso; VI Meeting of the Society for Free Radical Biology and Medicine – South American Group; 2009

Society for Free Radical Biology and Medicine South American Group

Exposure to environmental particulate matter is positively associated with increased cardiovascular morbidity and mortality, where the production of active oxygen and nitrogen species would be involved in the physiopathological mechanism. The aim of this work was to evaluate the cardiac oxidative metabolism in mice exposed to residual oil fly ash (ROFA). An in vivo acute model was used by a single intranasal instillation (0,20 mg/kg) of a ROFA suspension, in female Swiss mice weighing 25 g. Oxygen consumption was evaluated in tissue cubes, while NO production, superoxide dismutase (SOD) activity, catalase activity, TBARS and carbonyl content and total reactive antioxidant potential (TRAP) were determined in tissue homogenates. Measurements were made 3 h after exposure. Instillation with ROFA significantly decreased NO production by 43% (control value: 0.9 ± 0.1 nmol NO/min mg prot, p < 0.01). A significant increase was observed in SOD activity (control value: 2.3 ± 0.1 USOD/mg prot, p < 0.05) and in TRAP (control value: 4.0 ± 0.3 mM Trolox/mg prot, p < 0.05) by 25 and 52%, respectively. No significant differences were found in oxygen consumption by tissue cubes, as in catalase activity and TBARS and carbonyl content. Results showed the presence of an adaptative response as evidenced by the increased SOD activity and TRAP values. The decreased NO production could be associated with a diminution of the antinflammatory response triggered by the exposition to particulate matter.