Date of Award
1992
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
The research discussed in the following thesis falls under the general categories of organic chemistry and radiochemistry and the application of these disciplines to the development of imaging agents and labelling techniques for the branch of Nuclear Medicine involving single photon emitting radionuclides. The thesis is made up of three sections; one dealing with the synthesis, labelling and biological testing of a series of radioiodinated 2-nitrobenzyl alcohol derivatives as potential probes for tissue hypoxia; a second chapter dealing with the synthesis, labelling and biological testing of 1-(4- ({dollar}\sp{lcub}123{rcub}{dollar}I) -iodophenyl-2,6,7-trioxabicyclo- (2.2.2) octane as a potential imaging agent for the GABA{dollar}\sb{lcub}\rm A{rcub}{dollar} receptor and a third chapter which deals with a novel radiolabelling procedure based on an organotin polymer.;The radioiodinated 2-nitrobenzyl alcohol derivatives were tested in the EMT-6 tumour model in Balb/c mice to determine whether specific uptake was occurring in the tumours. The first compound in the series, O-(N-methyl carbamoyl),3-iodo-6-nitrobenzyl alcohol did not show specific tumour uptake and appeared to be metabolically deiodinated in vivo. The second compound tested, O-(N-methyl carbamoyl),4-iodo-6-nitrobenzyl alcohol did not show specific tumour uptake but showed a decrease in metabolic deiodination. A third compound, O-(N-methyl carbamoyl), 4-iodo-2,6-dinitrobenzyl alcohol, did appear to exhibit specific uptake in the tumour. Unfortunately, high levels of blood activity preclude the use of this compound as an hypoxia imaging agent.;1-(4- ({dollar}\sp{lcub}123{rcub}{dollar}I) -iodophenyl-2,6,7-trioxabicyclo- (2.2.2) octane was synthesized, labelled and was then tested in male CD1 mice for specific uptake in the brain. The compound underwent rapid metabolic elimination via the kidneys resulting in a short plasma half-life. The compound was found to be unacceptably lipophilic. The lipophilicity of the molecule coupled with its rapid metabolic elimination rendered it unsuitable as a receptor imaging agent.;A new polymer with aryltrialkyltin functions coupled to a polystyrene backbone was prepared. The specific aryl group used was N-isopropyl amphetamine. The new polymer was successfully employed in the synthesis of N-isopropyl-p- ({dollar}\sp{lcub}131{rcub}{dollar}I) iodoamphetamine. The method should have general applicability and may eliminate the need for chromatographic purification of some iodine radiopharmaceuticals.
Recommended Citation
Culbert, Paul A., "Bioreductive Alkylating Agents As Probes For Tissue Hypoxia" (1992). Digitized Theses. 2080.
https://ir.lib.uwo.ca/digitizedtheses/2080