In vivo upregulation of platelet number by dexamethasone (Dex) after intravenous administration of the of AdGRE.mTPO vector. The AdGRE.mTPO vector (5 × 108 pfu) was administered intravenously. (A) Dose-dependent increase in platelet number in C57B1/6 mice after dexamethasone administration for 1 to 3 successive days (50 μg/d) intraperitoneally. Platelet number was evaluated before and 4 to 22 days after vector administration. Shown are the platelet levels without dexamethasone (○), and with dexamethasone administered for 1 day (•), 2 days (▵), and 3 days (▴). (B) Platelet levels after administration of the AdNull control vector and dexamethasone. As a negative control, the AdNull vector (5 × 108 pfu) was injected intravenously to C57B1/6 mice with dexamethasone administered on 3 successive days (50 μg/d; intraperitoneal; •) or without dexamethasone (○). The platelet level was counted before and 4 to 22 days after vector administration. The data are presented as mean ± SE of three independent experiments.
