Abstract
Continuous exposure to 2 ppm nitric oxide (NO) for as long as 4 wk did not reduce the resistance of male mice to infection by aerosol inoculation with Pasteurella multocida. In contrast, mortality was slightly enhanced and survival shortened in NO‐exposed compared to control female mice; however, the importance of these small differences is uncertain. These results suggest only that male and female mice did not react similarly to the infectious challenge after exposure to NO.