Effects of Pretreatment with Anti-Inflammatory Drugs on Ozone-Induced Lung Damage in Rats

Abstract

Summary

The effects of pretreatment with acetylsalicylic acid (aspirin), hydrocortisone, indomethacin, and heparin administered ip against the pulmonary edema produced by O₃-exposure (4 ppm for 4 hr) were studied in rats. These anti-inflammatory drugs were found to alter the injurious effect of O₃ on lung differently. First, aspirin at the high dose (125 mg/kg) accentuated O₃-induced lung injury, and had no effect at the low dose (10 mg/kg); second, hydrocortisone (50 mg/kg) failed to have any effect; third, indomethacin at a high dose (20 mg/kg) offered a significant degree of protection, but had no effect at the low dose (2.5 mg/kg); and fourth, heparin (1000 units/kg) also offered a significant degree of protection against the lung damage normally induced by O₃-exposure. Several mechanisms for the favorable and unfavorable interactions of anti-inflammatory drugs with O₃-exposure are discussed.

This research was supported by the Davis Faculty Research Grant and the Chancellor's Patent Fund, University of California, Davis. We are also grateful to Dr. Walter Tyler, Director of the California Primate Research Center at Davis for allowing us the use of the ozone-exposure chamber facility.