The potential of radioiodinated (-)-m-iodovesamicol for diagnosing cholinergic deficit dementia

We investigated changes in the brain distribution of (-)-[I-125]-m-iodovesa micol [(-)-[I-125]mIV] in cholinergic denervation rats produced by a unilat eral lesion of the nucleus basalis magnocellularis (NBM). Dual-tracer ex vi vo autoradiographic analysis using (-)-[I-125]mIV and [Tc-99m]HMPAO was con ducted to the effect of regional cerebral perfusion on the brain distributi on of (-)-[I-125]mIV in a unilateral NBM-lesioned rat. (-)-[I-125]mIV bindi ng in the ipsilateral cortex to the lesion significantly reduced by 10.4 %, compared with that in the contralateral cortex, while (-)-[I-125]mIV bindi ng in the ipsilateral caudate putamen, hippocampus and thalamus did not cha nge. The rate of reduction in the (-)-[I-125]mIV binding (10.4 %) was signi ficantly higher than that of [Tc-99m]HMPAO accumulation (4.0%) in the ipsil ateral cortex to the lesion (P < 0.01). These results suggested that radioi odinated (-)-mIV may be useful in the study of dementia characterized by de generation of the cholinergic neurotransmitter system, such as Alzheimer's disease. (C) 2001 Elsevier Science Inc. All rights reserved.