Loading…
Desorption Electrospray Ionization Mass Spectrometry Imaging of Cimbi-36, a 5-HT2A Receptor Agonist, with Direct Comparison to Autoradiography and Positron Emission Tomography
Purpose The study demonstrates the use of Desorption Electrospray Ionization mass spectrometry imaging (DESI-MSI) for imaging of the PET tracer compound Cimbi-36 in brain tissue and compares imaging by DESI-MSI to imaging by autoradiography and PET. Procedures Rats were dosed intraperitoneally with...
Saved in:
Published in: | Molecular imaging and biology 2021-10, Vol.23 (5), p.676-685 |
---|---|
Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Purpose
The study demonstrates the use of Desorption Electrospray Ionization mass spectrometry imaging (DESI-MSI) for imaging of the PET tracer compound Cimbi-36 in brain tissue and compares imaging by DESI-MSI to imaging by autoradiography and PET.
Procedures
Rats were dosed intraperitoneally with 3 mg/kg of Cimbi-36 and euthanized at
t
= 5, 10, 15, 30, 60 and 120 min post-injection. The brains were removed, frozen and sectioned, and sagittal sections were imaged by DESI-MSI in positive ion mode. Additionally, brain sections from a non-dosed animal were incubated with
14
C-labelled Cimbi-36 and imaged by autoradiography. Finally, PET images were acquired from an animal dosed with
11
C-labelled Cimbi-36.
Results
DESI-MSI and autoradiography images of a sagittal brain sections showed similar distributions of Cimbi-36, with increased abundance in the frontal cortex and choroid plexus, regions which are high in 5-HT
2A
and 5-HT
2C
receptors. The PET image also showed increased abundance in cortex, but the spatial resolution was clearly inferior to DESI-MSI and autoradiography.
The DESI-MSI results showed increased abundance of Cimbi-36 in brain tissue until 15 min, after which the abundance was declining. The PET-tracer was still clearly detectable at
t
= 120 min. Similar imaging of the kidneys showed the abundance of Cimbi-36 peaking at 30 min. Cimbi-36 was quantified in a
t
= 15 min brain section by quantitative DESI-MSI, resulting in tissue concentrations of 19.8 μg/g in cortex, 15.4 μg/g in cerebellum and 12.5 μg/g in whole brain.
Conclusions
DESI imaging from an
in vivo
dosing experiment showed distribution of the PET tracer remarkably similar to what was obtained by autoradiography of an
in vitro
incubation experiment, indicating that the obtained results represent actual binding to certain receptors in the brain. DESI-MSI is suggested as a cost-effective screening tool, which does not rely on labelling of compounds. |
---|---|
ISSN: | 1536-1632 1860-2002 |
DOI: | 10.1007/s11307-021-01592-2 |