Administration of beta-aminopropionitrile to human beings with urethral strictures: A prelimary report.

(1) No toxic signs or symptoms and no unusual laboratory determinations were observed in five patients with posterior urethral strictures treated by dilatation of the urethra and administration of 1 gm per day of beta-aminopropionitrile (BAPN) for twenty-one days. (2) Patients treated with 1 gm daily of BAPN for twenty-one days showed an increase in cold saline-extractable and acid-extractable collagen in proplast sponge-collected and dermal scar tissue comparable with that reported previously after doses of 3 to 5 gm of BAPN daily. (3) Significant reduction in the breaking strength of newly synthesized connective tissue was observed in patients treated with BAPN. (4) None of the patients in this study showed abnormalities in net collagen synthesis or in synthesis of noncollagenous protein. (5) The difference in the results of this study and two previous trials of BAPN in human beings which were discontinued because of toxic and or hypersensitivity signs and symptoms is hypothesized to be the result of development of highly purified BAPN fumarate.