Figure 3

Study protocols for cigarette smoke exposure in mice. A) For the one-week smoke model protocol, mice were treated by endo-tracheal delivery of combined 4B/4D + 7A AON on days 1, 3, 6 and 8. On days 6 to 9, other groups of mice were treated daily with oral roflumilast. On days 6 to 9 (3 h after AON or roflumilast treatment), mice were nose-only exposed to the smoke of two 2R4f reference cigarettes per day. Bronchoalveolar lavages (BAL) were performed on Day 10. B) For the two-week smoke model protocol, mice were treated by endo-tracheal delivery of combined 4B/4D + 7A AON daily from Day 1 to Day 5, then once a week on Day 8 and 15. On days 8 to 12 and 15 to 18, mice were nose-only exposed to the smoke of two 2R4f reference cigarettes per day. BAL were performed on Day 19.