[18F]SPA-RQ/PET Study of NK1 receptors in the Whole Body of Guinea Pig and Rat

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Tove J. Grönroos, Sarita Forsback, Olli Eskola, Jörgen Bergman, Päivi Marjamäki, Eliisa Löyttyniemi, Jarmo Hietala, Merja Haaparanta-Solin, Olof Solin
Publisher: Nature Research
Publication year: 2019
Journal: Scientific Reports
Journal acronym: Sci Rep
Volume number: 9


There is a substantial interest in the development of NK1 substance P
antagonists as potential treatments for various neuropsychiatric and
somatic disorders. The aim of this study was to determine whether [18F]SPA-RQ
can be utilized as a tool for studying the whole body distribution and
function of NK1 receptors in preclinical settings. The compound was
injected into guinea pigs with or without premedication with a NK1
receptor antagonist (NK1A-2). For comparison, we included two rats in
the study, as the affinity of antagonists for NK1 receptors is known to
vary between species. The whole body biodistribution of the tracer was
determined at several time points. The tracer showed specific binding in
organs compatible with the known location of NK1-receptors.
Premedication with a NK1 antagonist led to an inhibited uptake of [18F]SPA-RQ
in several organs of guinea pigs, notably intestine, pancreas, urinary
bladder, uterus, skin and lung. Specific binding was also seen in both
cortex and striatum. In contrast, negligible specific binding was
observed in the rat brain with [18F]SPA-RQ, whereas the tracer uptake in peripheral tissues was similar to that seen in guinea pigs. We conclude that [18F]SPA-RQ/PET
is a useful tool to study the distribution and function of peripherally
located NK1 receptors e.g. in different disease models.

Last updated on 2020-23-09 at 05:50