Effect of hydrogen sulfide on bacterial inactivation in the rat lung.

This study evaluated the effect of a low concentration of hydrogen sulfide on the rat antibacterial defense system. Rats exposed to 45 ppm hydrogen sulfide (threshold limit value for hydrogen sulfide = 10 ppm) for 4 or 6 hr exhibited a significant (P less .01) reduction in the inactivation of viable staphylococci deposited in the lungs during a bacterial aerosol challenge. Pre-exposure of rats to 46 ppm hydrogen sulfide for 2 hr, however, did not alter intrapulmonary staphylococcal inactivation. We hypothesize that impairment of the alveolar macrophage is the basis of these findings.