Enhancement of rat serum ceruloplasmin levels by exposure to hyperoxia.

Exposure of rats to elevated oxygen tensions is a well-known method of producing enhanced levels of pulmonary antioxidant enzymes. Ceruloplasmin is a serum constituent which possesses scavenging activity toward oxygen radicals. Rats exposed either to continuous 85% oxygen for 7 days or to intermittent hyperbaric oxygen for up to 19 days developed not only enhanced lung antioxidant enzymes but also increased levels of serum ceruloplasmin. The latter did not appear to be merely an "acute phase reactant" as there was no change in total serum protein, plasma fibrinogen, serum -SH groups, sedimentation rate, or serum iron. Induction of ceruloplasmin may account for some of the anti-inflammatory activities of elevated oxygen tensions.