Immunological function in mice chronically exposed to nitrogen oxides (NO x)

Abstract

BALB c mice were exposed to 10 ppm NO or NO 2 for 2 hr daily on weekdays, for varying periods up to 30 weeks. At intervals of approximately 7 weeks, groups of animals were subjected to a variety of pathological and immunological examinations: serum antibody responses to both T-dependent and T-independent antigens, spleen cell PHA and graft-versus-host responses, capacity to reject a transplanted tumor, routine hematology, and lung pathology. Tests of immune function indicated suppression resulting from chronic exposure to these gases, and in most cases data indicated enhancement of immunological reactivity by shorter exposures. NO 2 appeared somewhat more potent than NO in this regard, but the differences observed were not great. Chronic NO exposure produced a more severe lung pathology, with clear evidence of paraseptal emphysema.