Effects of acute exposure to nitrogen dioxide on primary antibody response.

The effects of acute exposure to nitrogen dioxide on primary humoral antibody response to sheep red blood cells in mice were studied. Mice were exposed to 5 ppm, 20 ppm, and 40 ppm nitrogen dioxide for 12 hr. An exposure of 20 ppm or 40 ppm resulted in a significant suppression of antibody responses, but 5 ppm did not affect antibody response. This immunosuppression resulting from nitrogen dioxide exposure was more apparent in males than females. Exposures to 20 ppm nitrogen dioxide for various time intervals revealed that the strongest suppression effect was observed in the group exposed 2 days after antigen injection. A decreased total cell number in the spleen, and more strikingly, in the thymus, was also caused by acute exposure to nitrogen dioxide.