Effect of human alpha-antitrypsin in papain-induced emphysema in the hamster

The possibility that human alpha1-antitrypsin could effectively prevent development of emphysematous lesions produced in hamsters 7 days after exposure to aerosolized papain (3% for 3 hours) was investigated. Pretreatment with intratracheal human alpha1-antitrypsin prevented the appearance of these lesions in a dose-dependent manner. On the other hand, systemic administration of large doses of human alpha1-antitrypsin failed to prevent papain-induced pulmonary lesions, despite a significant increase in serum trypsin inhibitory capacity. These results suggest that intra-alveolar rather than serum concentrations of human alpha1-antitrypsin are critical for preventing the development of pulmonary emphysema in this animal model. It is interesting that although the mechanism by which human alpha1-antitrypsin prevented the papain-induced lesions is unknown, intratracheally administered human alpha1-antitrypsin similarly prevented the development of pulmonary emphysematous lesions induced by 0.1 mg of porcine pancreatic elastase given intratracheally.