NITROGEN-DIOXIDE-INDUCED EMPHYSEMA IN RATS - LACK OF WORSENING BY BETA-AMINOPROPIONITRILE TREATMENT

We evaluated the effect of beta-aminopropionitrile (.beta.APN) on the nitrogen dioxide (NO2) animal model of emphysema. Rats maintained on a .beta.APN-supplemented or a regular diet were exposed to 30 ppm NO2 for intervals ranging from 1 to 8 wk. Emphysema development was assessed by histologic evaluation and by changes in lung volume and mean linear intercept values. Evidence of pathologic changes were also documented by clinical and radiographic findings of osteolathyrism. The induction of centriacinar emphysema was attributed specifically to NO2 exposure. Neither the severity of the emphysema nor the time course of its development was altered by the .beta.APN-supplemented diet. These findings are in marked contrast to those observed with the exogenous elastase model of the disease, and they suggest that elastin synthesis and repair may not modulate elastin destruction in the NO2 model of emphysema.