Development of a Radioiodinated Probe for in Vivo Detection of Lipid Radicals and Evaluation Using Middle Cerebral Artery Occlusion Model

Abstract

Free radicals, such as hydroxyl radical, superoxide, and lipid-derived radical, have unpaired electrons, making them a highly reactive chemical species. They play important physiological roles, for example, in the removal of xenobiotic substances, such as bacteria and viruses, and in the production of chemical mediators, like prostaglandins and leukotrienes. However, excessive production of free radicals can cause structural defects in biomolecules like DNA and proteins, resulting in a loss of their normal functions. Hence, free radicals have been implicated in the onset and progression of various diseases such as cancer, atherosclerosis, and neurodegenerative diseases. However, there is very little clarity on the substantial amount, type, and location of free radicals in vivo, under pathological conditions. An investigation on the actual state of free radicals in vivo could lead to the diagnosis of pathological conditions and the elucidation of the mechanisms of their onset and progression; therefore, the development of in vivo radical detection methods is being widely pursued. Toward this end, nuclear medical imaging methods have recently attracted attention. In this study, we discuss the development of a nuclear medical imaging probe for the specific targeting of lipid radicals.