Effect of intermittent hyperbaric oxygen on adjuvant and collagen arthritis in rats: Lack of correlation with activity of oxygen radical scavenging enzymes.

Abstract

We have confirmed a previous report that intermittent hyperbaric oxygen (HBO, 6 h of 100% oxygen at 2 atm followed by 18 h of normobaric room air) ameliorated adjuvant disease of rats, although the magnitude of the effect was less than that previously reported and was found to be done and strain dependent. We have extended the findings to another rat model, collagen arthritis, the manifestations of which were also suppressed, as were anticollagen antibody titers. The effect was not due to generalized antinflammatory activity, as carrageenan edema was unaffected. No correlation with induction of oxygen radical scavengers such as superoxide dismutase or catalase could be demonstrated. Hyperbaric air (as opposed to oxygen) had no effect. Peritoneal macrophage function from HBO-treated rats was normal. HBO has a mild but consistent suppressive effect on rodent arthritis under controlled laboratory conditions, the mechanism of which may relate to immunomodulation.