EFFECTS OF OZONE EXPOSURE IN RATS ON MEMORY AND LEVELS OF BRAIN AND PULMONARY SUPEROXIDE-DISMUTASE

Exposure to ozone results in increased production of free radicals, wh ich causes oxidative stress. The objective of this study was to determ ine the effect of different doses of ozone exposure on memory and to c orrelate this with pulmonary and brain Cu/Zn superoxide dismutase (SOD ) levels. Male Wistar rats were exposed for 4 h to one of the followin g ozone concentrations: 0, 0.1, 0.2, 0.5, or 1 ppm. Subsequently, they were tested in a passive avoidance conditioning protocol to measure s hort and longterm memory. Motor activity was determined 1 and 24 h aft er ozone exposure. Cu/Zn SOD levels in the brain and pulmonary tissue were also measured. Rats exposed for 4 h to 0.2, 0.5, and 1 ppm ozone showed long-term memory deterioration and decreased motor activity, wh ich was reversed 24 h later. Brain and pulmonary Cu/Zn SOD levels were increased in animals exposed to 0.1, 0.2, and 0.5 ppm ozone doses, bu t decreased in animals exposed to 1 ppm ozone. The results suggest tha t ozone exposure affects long-term memory possibly in association oxid ative stress. (C) 1998 Academic Press.