Validation and quantification of [18F]altanserin binding in the rat brain using blood input and reference tissue...

Area of Science:

• Neuroscience
• Radiochemistry
• Pharmacology

Background:

• The 5-hydroxytryptamine type 2a (5-HT(2A)) receptor is a key target in neuroscience.
• Developing selective radiotracers is crucial for in vivo receptor quantification.
• [(18)F]altanserin is a potential PET tracer for 5-HT(2A) receptors.

Purpose of the Study:

• To evaluate the suitability of [(18)F]altanserin for quantitative positron emission tomography (PET) studies.
• To compare metabolite-corrected plasma input modeling with reference tissue modeling for [(18)F]altanserin kinetics.
• To assess the brain uptake, distribution, and metabolism of [(18)F]altanserin in rats.

Main Methods:

• Quantitative micro-PET imaging in Lister Hooded rats.
• Application of metabolite-corrected plasma input modeling.
• Comparison with reference tissue modeling using the cerebellum.
• Assessment of binding saturation and displacement.

Main Results:

• [(18)F]altanserin demonstrated adequate brain uptake and distribution consistent with 5-HT(2A) receptor patterns.
• No significant uptake of radioactive metabolites was observed in the brain.
• Both blood input and reference tissue models accurately described radiotracer kinetics.
• Full binding saturation and displacement were confirmed.

Conclusions:

• [(18)F]altanserin is a suitable radiotracer for quantifying 5-HT(2A) receptor availability in rats.
• Both modeling approaches are appropriate for kinetic analysis of [(18)F]altanserin.
• The tracer shows promise for preclinical neuroscience research involving 5-HT(2A) receptors.