SUMMARYMedetomidine, a highly specific a-2 adrenergic agonist, has been demonstrated to lower intraocular pressure (lOP) in rabbits and cats when applied topically. The purpose of this study was to assess the influence of intravenously injected medetomidine on the pupil size (PS) and the IOP of non glaucomatous dogs.

Two radiolabeled bicyclic nucleoside analogues (BCNAs) were synthesized, namely 3-(2'-deoxy-beta-d-ribofuranosyl)-6-(3-[18F]fluoroethoxyphenyl)-2,3-dihydrofuro[2,3-d]pyrimidin-2-one ([18F]-2) and 3-(2'-deoxy-beta-d-ribofuranosyl)-6-(3-[11C]methoxyphenyl)-2,3-dihydrofuro[2,3-d]pyrimidin-2-one ([11C]-3), and evaluated as PET reporter probes for varicella-zoster virus thymidine kinase (VZV-tk) gene expression imaging in brain. [18F]-2 and [11C]-3 were synthesized starting from phenol precursor 1. The phenol precursor 1 was converted to stable as well as to radiolabeled compounds 2 and 3 using (19/18)FCH(2)CH(2)Br or (12/11)CH(3)I as alkylating agent. In vitro evaluation of [18F]-2 and [11C]-3 in 293T cells showed a 4.5 and 53-fold higher uptake, respectively, into VZV-tk gene-transduced cells compared to control cells. However, biodistribution studies in mice demonstrated low uptake of these tracers in the brain. RP-HPLC analysis of plasma and urine samples of mice injected with [11C]-3 revealed that this tracer is very stable in vivo. These data warrant further evaluation of these tracers as noninvasive imaging agents for VZV infection and VZV-tk reporter gene expression in vivo.

No abstract

No abstract