Abstract
The radiochemical syntheses of 5-[125I]iodo-3-(2(S)- azetidinylmethoxy)pyridine (5-[125I]-iodo-A-85380, [125I]1) and 5- [123I]-iodo-A-85380, [123I]1, were accomplished by radioiodination of 5-trimethylstannyl-3-((1-tert-butoxycarbonyl-2(S)- azetidinyl)methoxy)pyridine, 2, followed by acidic deprotection. Average radiochemical yields of [125I]1 and [123I]1 were 40-55%; and the average specific radioactivities were 1,700 and 7,000 mCi/μmol, respectively. Binding affinities of [125I] 1 and [123I] 1 in vitro (rat brain membranes) were each characterized by a K(d) value of 11 pM. Preliminary in vivo assay and ex vivo autoradiography of mouse brain indicated that [125I]1 selectively labels nicotinic acetylcholine receptors (nAChRs) with very high affinity and specificity. These studies suggest that [123I]1 may be useful as a radioligand for single photon emission computed tomography (SPECT) imaging of nAChRs.
Original language | English (US) |
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Pages (from-to) | 175-182 |
Number of pages | 8 |
Journal | Nuclear Medicine and Biology |
Volume | 26 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1 1999 |
Externally published | Yes |
Keywords
- A-85380
- Acetylcholine
- I
- I
- Nicotinic receptors
- Radioiodination
- Radiotracer
- Receptor binding
- SPECT
ASJC Scopus subject areas
- Molecular Medicine
- Radiology Nuclear Medicine and imaging
- Cancer Research