Figure 7.

Accumulation of [³H]-verapamil and [¹⁴C]-sucrose in rat brain following in situ brain perfusion. (A) Time course of [³H]-verapamil (0.1 μCi/mL) brain accumulation in rats perfused for 10, 15, or 20 min in the absence (●) or presence of QT (10 μM) or QT₂C₂Me₂ (8) (10 μM) (▲). Brain samples were processed as described in Methods, and the accumulated radioactivity was quantified by scintillation counting. Data (R_br, μL g^–1) are expressed as the ratio of radioactivity in the brain (dpm g^–1) to that of perfusate (dpm μL^–1). (B, C) Brain accumulation of (B) [³H]verapamil or (C) [¹⁴C]sucrose in rats perfused for 20 min in the presence or absence of 10 μM QT or QT₂C₂Me₂ (8). Cyclosporin A (CsA) was used as a positive control. Shown are mean ± SEM for 6–8 rats. Statistical comparisons: one-way ANOVA, ***P < 0.001, ****P < 0.0001.