Ozone Effects on Protein Carbonyl Content in the Frontal Cortex and Cerebellum of Young-Adult, Middle Age, and Senescent Brown Norway Rats
Kodavanti, P., Joyce E. Royland, Judy E. Richards, D. Agina-Obu, AND R. MacPhail. Ozone Effects on Protein Carbonyl Content in the Frontal Cortex and Cerebellum of Young-Adult, Middle Age, and Senescent Brown Norway Rats. Society of Toxicology (SOT) Annual Meeting, San Diego, CA, March 23 - 27, 2015.
This abstract will be presented at the Society of Toxicology (SOT) Annual Meeting March 23-27, 2014, San Diego, CA
Oxidative stress (OS) plays an important role in susceptibility and disease in old age. Understanding age-related susceptibility is a critical part of community-based human health risk assessment of chemical exposures. There is growing concern over a common air pollutant, ozone (03), and adverse health effects including dysfunction of the pulmonary, cardiac, and nervous systems. The objective of this study was to test whether OS plays a role in the adverse effects caused by 03 exposure, and if so, if effects were age-dependent. We selected protein carbonyl as an indicator of OS because carbonyl content of cells is a useful indicator of oxidative protein damage and has been linked to chemical-induced adverse effects. Male Brown Norway rats (4, 12, and 24 months) were exposed to 03 (0,0.25 or 1 ppm) via inhalation for 6 h/day, 2 days per week for 13 weeks. Frontal cortex (FC) and cerebellum (CB) were dissected, quick frozen on dry ice, and stored at -80°C. Protein carbonyls were assayed using commercial kits. Hydrogen peroxide, a positive control, increased protein carbonyls in cortical tissue in vitro in a concentration-dependent manner. Significant effects of age on protein carbonyls in FC and a significant effect of age and 03 dose on protein carbonyls in CB were observed. In control rats, there was an age-dependent increase in protein carbonyls indicating increased OS in 12 and 24 month old rats compared to 4 month old rats. Although 03 increased protein carbonyls in both brain regions and in all age groups, 03 effects were statistically significant only in the 4 month old rats. These results indicate that FC and CB of 4 month old rats are more susceptible to oxidative damage caused by 03 when compared to those from12 month and 24 month old rats. (This abstract does not necessarily reflectUSEPA policy).