Add like
Add dislike
Add to saved papers

Evaluation in monkey of two candidate PET radioligands, [ 11 C]RX-1 and [ 18 F]RX-2, for imaging brain 5-HT 4 receptors.

Synapse 2014 December
The serotonin subtype-4 (5-HT4 ) receptor, which is known to be involved physiologically in learning and memory, and pathologically in Alzheimer's disease, anxiety, and other neuropsychiatric disorders-has few radioligands readily available for imaging in vivo. We have previously reported two novel 5-HT4 receptor radioligands, namely [methoxy-11 C](1-butylpiperidin-4-yl)methyl 4-amino-3-methoxybenzoate; [11 C]RX-1), and the [18 F]3-fluoromethoxy analog ([18 F]RX-2), and in this study we evaluated them by PET in rhesus monkey. Brain scans were performed at baseline, receptor preblock or displacement conditions using SB 207710, a 5-HT4 receptor antagonist, on the same day for [11 C]RX-1 and on different days for [18 F]RX-2. Specific-to-nondisplaceable ratio (BPND ) was measured with the simplified reference tissue model from all baseline scans. To determine specific binding, total distribution volume (VT ) was also measured in some monkeys by radiometabolite-corrected arterial input function after ex vivo inhibition of esterases from baseline and blocked scans. Both radioligands showed moderate to high peak brain uptake of radioactivity (2-6 SUV). Regional BPND values were in the rank order of known 5-HT4 receptor distribution with a trend for higher BPND values from [18 F]RX-2. One-tissue compartmental model provided good fits with well identified VT values for both radioligands. In the highest 5-HT4 receptor density region, striatum, 50-60% of total binding was specific. The VT in receptor-poor cerebellum reached stable values by about 60 min for both radioligands indicating little influence of radiometabolites on brain signal. In conclusion, both [11 C]RX-1 and [18 F]RX-2 showed positive attributes for PET imaging of brain 5-HT4 receptors, validating the radioligand design strategy. Synapse 68:613-623, 2014. © 2014 Wiley Periodicals, Inc.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app