Beta-aminopropionitrile as a radiation reaction preventive agent.

Beta-aminopropionitrile (BAPN), an inhibitor of collagen maturation, was tested as a radiation reaction preventive agent (RRPA) using radiation-induced lung fibrosis in rats and mice as a model. Following pulmonary irradiation, treatment with BAPN significantly prevented an increase in collagen content as measured by hydroxyproline analysis. This effect persisted during BAPN maintenance for periods of up to 10 weeks but was lost when the drug was discontinued. BAPN administration did not increase the mouse lung LD50/160 in the drug doses employed in this study. Other possible RRPAs deserving further study include D-penicillamine and beclomethasone dipropionate.