Fig. 4

Lassen plot to determine cyclooxygenase-2 (COX-2) occupancy and non-displaceable uptake (V_ND) of [¹¹C]MC1 in brain after a single lipopolysaccharide (LPS) injection in monkey 2. Each point represents a brain region from a single animal scanned twice in one day: at baseline and after enzyme blockade by MC1 (0.3 mg/kg i.v. administered five minutes before the second radioligand injection). The slope of the straight-line fit provides the occupancy (78%), meaning that MC1 occupied 78% of all COX-2 molecules. The x-intercept provides the V_ND (4.3 mL cm⁻³)