Effect of Santoquin on humoral immune function in mice: lack of interference with selenium utilization

Santoquin (0.25% by weight) in the diets of mice receiving adequate dietary selenium (1.0 parts/10(6] reduced the humoral immune response, as monitored by the plaque-forming cell assay, to levels exhibited by mice maintained on selenium-deficient diets (0.005 parts/10(6)). Mice exhibiting this suppression of immunity had levels of blood glutathione peroxidase, serum selenium, and liver DNA, RNA and protein similar to mice receiving selenium only. Therefore, it was concluded that Santoquin is not immunosuppressive by interfering with selenium metabolism or general tissue function, but by other unknown mechanisms.