Figure 2.
Lassen plots for [11C]T1660 and [11C]T1650 in monkey based on total distribution volume (VT) measured by two-tissue compartment modeling in monkey brain. Target occupancy is given by the slope, while the non-displaceable tracer volume (VND) is given by the X-axis intercept. A: Comparison of Lassen plots for [11C]T16550 and [11C]T1660 in which rolipram was used as a preblocker at 1.0 mg/kg, i.v. B: Effect of reducing rolipram intravenous preblock dose from 1.0 mg/kg to 0.2 mg/kg on Lassen plot, showing decreased slope (occupancy). C. Comparison of Lassen plots for use of rolipram at 1.0 mg/kg (i.v.) or BPN14770 at 3.0 mg.kg (i.v.) as preblocking agent for [11C]T1650. Note all Lassen plots gave similar VND values for [11C]T1650. For the use of BPN as preblocker, binding potential (BPND) for whole brain was estimated to be 1.2.