Dopamine transporters are protein complexes ocated at the presynaptic (forepart) of dopamine nerve terminals which function to deliver messages to receptors in the brain. A significant reduction in the density of these transporters has been found in postmortem examinations of the brains of Parkinson's and Alzheimer's patients. Thus, measurement of the dopamine transporter with Trodat could be a useful indicator of dopamine neural loss. With advanced radiologic imaging technology, such as single positron emission tomography (SPET) -- which works by emitting photons or light -- Trodat can be a valuable tool for live diagnosis and treatment of illnesses associated with dopamine transporters. Such illnesses include Parkinson's and Alzheimer's, as well as schizophrenia and ALS (Lou Gehrig's disease).
In this study, Trodat was intravenously injected into rats. Trodat displayed specific brain uptake in the rats' striatal region of the brain where dopamine neurons are concentrated. The study's findings strongly support the conclusions that Trodat binds selectively to dopamine transporters in the brain and that it is potentially useful in the assessment of neuron loss. Compared to other imaging agents, Trodat is favorable because it involves very little radioactivity, has a six-hour physical half-life, and is inexpensive. This tracer, coupled with SPET imaging, can provide diagnostic information not attainable by other imaging techniques, including early indications of diseases associated with dopamine changes. Research continues into more advanced stages with goals to ultimately translate findings into clinical applications for patients. Recently, research has progressed to human studies using Trodat.
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Contact: Diane Giaccone
University of Pennsylvania School of Medicine