Radiopharmaceuticals for SPECT exploration of dopaminergic systems. Diagnosis and surveillance of neuro-degenerative diseases

New radiopharmaceuticals were developed to explore the pre- or post-synaptic slopes of the dopaminergic terminations. At present, their interest is recognized for the differential diagnosis of the extra-pyramidal syndromes. Other various applications in neurology and psychiatry are in view. On the pre-synaptic slope, implied in the Parkinson's disease, the dopamine carrier, able to be visualized due to its iodine derivatives of cocaine, is localized. The βCIT, which is presently the best known specificity-free derivative, has actually an equivalent affinity for the dopamine carrier and the serotonin carrier. Besides, its kinetic does not allow its imaging in the day of injection. We have developed and validated another derivative, the PE2I: N-(3-Iodoprop-(2E)-enyl) -2β-carbometoxy -3β-(4'-methyl-phenyl) nortropane which displays the properties required by kinetic and specificity. On the post-synaptic slope the type-D2 dopaminergic receptors were localized, which can be explored by means of (iodolisuride) ergolenes and benzamide derivatives (IBZM). These ligands have not an AMM yet, therefore their utilization may be approached by magistral preparation. The scintigraphy of the D2 receptors and dopamine carrier could be useful for the earlier diagnosis and the therapeutic surveillance of the neuro-degenerative decease. The coupling of the pre- and post-synaptic scintigraphies may be taken into consideration to augment diagnosis potentiality