Platelet levels in peripheral blood of mice after chronic APAS or busulfan administration. (A) APAS or CS was administered intramuscularly (0.1 mL) at 0 hours and blood was collected via retro-orbital bleed or via cardiac puncture (third and final bleed). (B) Platelet depletion recorded over chronic period with APAS or CS administration twice weekly (blood taken 24 hours after any previous injection of APAS or CS). In the case of busulfan (C), mice were exposed to aerosolized OVA (1%) for 8 weeks and busulfan (25 mg/kg, intraperitoneally) was administered once fortnightly throughout the period of exposure. Each point represents the mean and vertical lines the standard error of the mean of 2 to 4 observations.