IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Lung oxidative metabolism after an acute exposure to transition metals present in ambient particulate matter
Autor/es:
MAGNANI, NATALIA; MARCHINI, TIMOTEO; MEBERT, ANDREA; TASAT, DEBORAH; DESIMONE, MARTIN; DIAZ, LUIS; ALVAREZ, SILVIA; EVELSON, PABLO
Lugar:
Punta del Este
Reunión:
Simposio; XII International Symposium on Metal Ions in Biology and Medicine; 2013
Resumen:
Transition metals present in particulate matter (PM) could alter lung oxidative metabolism due to their ability to participate in Fenton reactions thus increasing reactive oxygen species production. The aim of this work was to study lung oxidative metabolism after an acute exposure to Residual Oil Fly Ashes (ROFA) and transition metals present in PM. Mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight) or silica nanoparticles (NP) containing Ni or Cr adsorbed to its surface (0.01-1.00 mg Ni/kg body weight). Lung samples were analysed 1 h after instillation. Tissue O2 consumption, NADPH oxidase (Nox) activity and TBARS content were evaluated after PM and NP exposure. Mitochondrial respiration, H2O2 and ATP production rates, mitochondrial membrane potential and oxidative damage markers were assessed in isolated mitochondria after ROFA treatment.ROFA exposure was found to be associated with 61% increased tissue O2 consumption, a 30% increase in Nox activity, and a 33% increased mitochondrial active respiration (state 3). During state 3, decreased mitochondrial membrane potential and a 53% decreased ATP production rate were observed. No changes were found in either H2O2 production rate or oxidative damage markers in isolated mitochondria. Regarding NP exposure, tissue O2 consumption, Nox activity and TBARS were found significantly increased in every Ni concentration assessed, while NP coated with Cr only showed significantly increased O2 consumption and TBARS content at 0.05 mg/kg. After ROFA exposure, increased tissue O2 consumption may account for an augmented Nox activity and mitochondrial respiration. The mitochondrial function modifications observed may prevent oxidative damage within the organelle. Transition metals like Ni or Cr present in PM seem to be important components involved in the altered lung oxidative metabolism after ROFA exposure. These findings provide new insights to the understanding of lung oxidative damage mechanisms triggered by metals present in environmental PM.