Oxymetholone modulates cell-mediated immunity in male B6C3F1 mice

Oxymetholone is a synthetic androgen, structurally related to testosterone. It is currently used to treat anemias, but has also been abused as a perfo rmance enhancing anabolic steroid by the sport community. Concern about its suspected immunomodulatory properties provided the incentive for a detaile d investigation into its effects on the mammalian immune system. In this st udy, male B6C3F1 mice were treated for 14 d with oxymetholone (0, 50, 150, and 300 mg/kg) by gastric intubation, then evaluated for immunotoxicity usi ng a panel of immunotoxicity assays. Except for an increasing trend in kidn ey and liver weights, and a dose-dependent increase in serum blood urea nit rogen levels, no other signs of systemic toxicity were observed. Bone marro w DNA synthesis was reduced, though this did not translate into alterations in myeloid or monocyte colony forming units. Spleen B and T cell numbers, antibody response to sheep red blood cells, proliferative response to both mitogen and immunoglobulin receptor immunogens, and NK cell activity were a ll unaltered in mice treated with oxymetholone. Peritoneal macrophage activ ity was also unaffected by oxymetholone treatment. A 38% decrease in the sp leen cell mixed leukocyte response, and a 15% decrease in cytotoxic T cell activity, measured in the highest oxymetholone treatment group, indicate th at cell-mediated immunity was impaired following exposure. This immunomodul ation did not however, translate into a change in host resistance to Lister ia monocytogenes.