Protection with cycloheximide or emetine against pulmonary edema induced by ozone or nitrogen dioxide

Pretreatment with cycloheximide or emetine provided significant protection against pulmonary edema in rats exposed to ozone or nitrogen dioxide. Other inhibitors of protein-synthesis, actinomycin D or puromycin, failed to show such effects. Possible actions of these agents as well as the doses and times that afforded the significant protection were investigated. These agents, by themselves, did not alter the water content of the lungs. In vitro study revealed that both cycloheximide and emetine hardly acted as scavengers of oxidant. Pretreatment with either agent was associated with a significant increase in the activity of glucose 6-phosphate dehydrogenase of the lungs, but the increase did not necessarily coincide with the protection. Activity levels of non-protein SH, glutathione-peroxidase and -reductase in the lungs of rats treated with either agent were scarcely altered. The effect of these agents administered in vivo or in vitro on the in vitro lipid peroxidation by air was also investigated. Other possible mechanisms of these agents responsible for the protective effect against pulmonary edema induced by oxidants were also discussed.