title: Probes for the dopamine transporter: new leads toward a cocaine-abuse therapeutic--A focus on analogues of benztropine and rimcazole.
abstract: In an attempt to discover a cocaine-abuse pharmacotherapeutic, extensive investigation has been directed toward elucidating the molecular mechanisms underlying the reinforcing effects of this psychostimulant drug. The results of these studies have been consistent with the inhibition of dopamine uptake, at the dopamine transporter (DAT), which results in a rapid and excessive accumulation of extracellular dopamine in the synapse as being the mechanism primarily responsible for the locomotor stimulant actions of cocaine. Nevertheless, investigation of the serotonin (SERT) and norepinephrine (NET) transporters, as well as other receptor systems, with which cocaine either directly or indirectly interacts, has suggested that the DAT is not solely responsible for the reinforcing effects of cocaine. In an attempt to further elucidate the roles of these systems in the reinforcing effects of cocaine, selective molecular probes, in the form of drug molecules, have been designed, synthesized, and characterized. Many of these compounds bind potently and selectively to the DAT, block dopamine reuptake, and are behaviorally cocaine-like in animal models of psychostimulant abuse. However, there have been exceptions noted in several classes of dopamine uptake inhibitors that demonstrate behavioral profiles that are distinctive from cocaine. Structure-activity relationships between chemically diverse dopamine uptake inhibitors have suggested that different binding interactions, at the molecular level on the DAT, as well as divergent actions at the other monoamine transporters may be related to the differing pharmacological actions of these compounds, in vivo. These studies suggest that novel dopamine uptake inhibitors, which are structurally and pharmacologically distinct from cocaine, may be developed as potential cocaine-abuse therapeutics.
authors.affiliation: Medicinal Chemistry Section, National Institute on Drug Abuse--Intramural Research Program, National Institutes of Health, 5500 Nathan Shock Drive, Baltimore, Maryland 21224, USA. anewman@intra.nida.nih.gov
authors.forename: Amy Hauck
authors.initials: AH
authors.lastname: Newman
authors.forename: Santosh
authors.initials: S
authors.lastname: Kulkarni
mesh_terms: D001590:Benztropine / Q000031:analogs & derivatives*; D019970:Cocaine-Related Disorders / Q000188:drug therapy*; D050483:Dopamine Plasma Membrane Transport Proteins; D015195:Drug Design; D006801:Humans; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000187:drug effects*; D015335:Molecular Probes; D009419:Nerve Tissue Proteins
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D015335:Molecular Probes; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human; D001590:Benztropine