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Title: Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine

Abstract

The distribution of the racemic mixture of IQNP(1-Azabicyclo [2-2-2] oct-3-yl alpha-hydroxy-alpha-(1-iodo-propen-3-yl)-alpha-phenylacetate), a muscarinic antagonist was described earlier. Recently, the radioiodinated Z and E-(R,R) IQNP isomers have been prepared. Quantitative ARG studies using the Z and E isomers were performed in control rats and after pretreatment with ({plus_minus}) QNB or cocaine. High uptake of (Z)-IQNP was seen in the heart and brain with GI and urinary excretion. Lung uptake was lower than with the racemic IQNP. (Z)-IQNP uptake was maximal at 15 min p.i. with homogeneous distribution in the heart. In the brain, highest uptake was in the caudate, cortex, hippocampus, pons and thalamus. (Z)-IQNP showed higher cerebellar uptake and lower cortical uptake compared to (E)-IQNP. Clearance from brain was slower than bean. Heart and brain uptake of (E)-IQNP were markedly lower than the Z isomer. After QNB pretreatment, almost complete blocking of (Z)-IQNP uptake in heart and brain occurred. Cocaine did not significantly affect the distribution of IQNP. These data indicate that (Z)-IQNP has high affinity for the M2 muscarinic receptor with potential for brain and heart imaging. Cocaine appears to have little effect on the muscarinic-cholinergic receptors in the brain and heart.

Authors:
; ;  [1]
  1. Oak Ridge National Lab., TN (United States); and others
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY
OSTI Identifier:
198049
Report Number(s):
CONF-940605-
Journal ID: JNMEAQ; ISSN 0161-5505; TRN: 95:007029-0196
DOE Contract Number:  
AC02-76CH00016; AC05-84OR21400
Resource Type:
Journal Article
Journal Name:
Journal of Nuclear Medicine
Additional Journal Information:
Journal Volume: 35; Journal Issue: Suppl.5; Conference: 41. annual meeting of the Society of Nuclear Medicine, Orlando, FL (United States), 5-8 Jun 1994; Other Information: PBD: May 1994
Country of Publication:
United States
Language:
English
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; ACETATES; UPTAKE; AFFINITY; BRAIN; CLEARANCE; EXCRETION; HEART; HIPPOCAMPUS; ISOMERS; RATS; RECEPTORS; THALAMUS; IMAGES

Citation Formats

Som, P, Wang, G J, and Oster, Z H. Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine. United States: N. p., 1994. Web.
Som, P, Wang, G J, & Oster, Z H. Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine. United States.
Som, P, Wang, G J, and Oster, Z H. Sun . "Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine". United States.
@article{osti_198049,
title = {Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine},
author = {Som, P and Wang, G J and Oster, Z H},
abstractNote = {The distribution of the racemic mixture of IQNP(1-Azabicyclo [2-2-2] oct-3-yl alpha-hydroxy-alpha-(1-iodo-propen-3-yl)-alpha-phenylacetate), a muscarinic antagonist was described earlier. Recently, the radioiodinated Z and E-(R,R) IQNP isomers have been prepared. Quantitative ARG studies using the Z and E isomers were performed in control rats and after pretreatment with ({plus_minus}) QNB or cocaine. High uptake of (Z)-IQNP was seen in the heart and brain with GI and urinary excretion. Lung uptake was lower than with the racemic IQNP. (Z)-IQNP uptake was maximal at 15 min p.i. with homogeneous distribution in the heart. In the brain, highest uptake was in the caudate, cortex, hippocampus, pons and thalamus. (Z)-IQNP showed higher cerebellar uptake and lower cortical uptake compared to (E)-IQNP. Clearance from brain was slower than bean. Heart and brain uptake of (E)-IQNP were markedly lower than the Z isomer. After QNB pretreatment, almost complete blocking of (Z)-IQNP uptake in heart and brain occurred. Cocaine did not significantly affect the distribution of IQNP. These data indicate that (Z)-IQNP has high affinity for the M2 muscarinic receptor with potential for brain and heart imaging. Cocaine appears to have little effect on the muscarinic-cholinergic receptors in the brain and heart.},
doi = {},
journal = {Journal of Nuclear Medicine},
number = Suppl.5,
volume = 35,
place = {United States},
year = {1994},
month = {5}
}