Radiosynthesis and preliminary evaluation of 5-[(123/125)I]iodo-3- (2(S)-azetidinylmethoxy)pyridine: A radioligand for nicotinic acetylcholine receptors

Andrew Horti, Andrei O. Koren, Kan Sam Lee, Alexey G. Mukhin, D. Bruce Vaupel, Alane S. Kimes, Morgan Stratton, Edythe D. London

Research output: Contribution to journalArticle

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 languageEnglish (US)
Pages (from-to)175-182
Number of pages8
JournalNuclear Medicine and Biology
Volume26
Issue number2
DOIs
Publication statusPublished - Feb 1999
Externally publishedYes

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Keywords

  • I
  • I
  • A-85380
  • Acetylcholine
  • Nicotinic receptors
  • Radioiodination
  • Radiotracer
  • Receptor binding
  • SPECT

ASJC Scopus subject areas

  • Cancer Research
  • Molecular Medicine
  • Radiology Nuclear Medicine and imaging

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