Radiosynthesis and Evaluation of 11C-CIMBI-5 as a 5-HT2A Receptor Agonist Radioligand for PET
Journal of Nuclear Medicine October 18, 2010 Anders Ettrup, Mikael Palner, Nic Gillings et al. 50 citations
A radiolabeled agonist tracer, (11)C-CIMBI-5, was developed for PET imaging of the serotonin 2A (5-HT2A) receptor in the brain. In vitro assays showed CIMBI-5 is a high-affinity agonist at the 5-HT2A receptor. Ex vivo rat studies demonstrated a specific binding ratio of 0.77 ± 0.07 in the frontal cortex, which was reduced to cerebellar levels after ketanserin treatment, indicating selective binding. PET studies in pigs revealed a cortical binding potential of 0.46 ± 0.12 and a target-to-background ratio similar to the antagonist tracer (18)F-altanserin. Ketanserin treatment reduced cortical binding to cerebellar levels, confirming selective in vivo binding. (11)C-CIMBI-5 is a promising tool for investigating 5-HT2A agonist binding in the living human brain.