Lactate dehydrogenase activity and isoenzyme pattern in lungs, erythrocytes, and plasma of ozone-exposed rats and monkeys.
The effect of low levels of ozone exposure (8 hr daily for 7 days) on lactate dehydrogenase (LDH) activity and isoenzyme pattern was studied in the lungs, plasma, and erythrocytes of rats and monkeys. Exposure to 0.8 or 0.5 ppm ozone resulted in a significant increase in total LDH activvity in the lungs but not in the plasma and erythrocytes of rats. The LDH-5 fraction of the LDH isoenzymes was significantly decreased in terms of percentage distribution in the lungs and plasma of rats exposed to 0.8 ppm ozone, whereas the LDH-4 in the lungs and plasma and LDH-3 in the lungs were increased. At 0.5 ppm ozone, the isoenzyme distribution was not significantly changed in lungs, plasma, or erythrocytes. In monkeys, no significant change in either total LDH activity or isoenzyme pattern was observed in lungs, plasma, or erythrocytes after exposure to 0.8 ppm ozone.