Effects of nitric oxide on resistance to bacterial infection in mice.

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.