Effects of long-term treatment of mice with intrapulmonary heparin.

Intrapulmonary heparin calls for the administration of a single large dose of heparin. This results in a prolonged but low grade heparinemia lasting for many days. These features are quite different the response obtained from any of the currently used heparin regimens. A toxicity study was therefore conducted on mice exposed to heparin aerosol(7ppm) for 20 min, one a week for ten weeks. No deleterious effects were observed on physical and macroscopic examinations of the internal organs as well as on histological examination of tissues from most organs of the body.