Analysis of 5-HT2A Receptor Binding with [C-11]MDL 100907 in Rats: Optimization of Kinetic Modeling

Preclinical positron emission tomography studies are important to follow disease progression and develop new pharmacological agents. We investigated whether kinetic modeling of 5-HT2A tracer [C-11]MDL 100907 is possible in rats. Kinetic modeling with either metabolite-corrected plasma curve or with the cerebellum as a reference tissue resulted in a good correlation of nondisplaceable binding potential (BPND) calculated from a two-tissue compartment model (2TCM) or different reference tissue models. Injecting the tracer by a slower bolus decreases the variation in 2TCM outcome parameters and results in a good correlation between k(3)/k(4) and the other models. Application of 0.2 mg/kg cold MDL 100907 resulted in almost complete occupancy of 5-HT2A receptors. A reference tissue model can be used for [C-11]MDL kinetic modeling in rats, which is preferable in pharmacological or longitudinal studies