title: A tobacco extract containing alkaloids induces distinct effects compared to pure nicotine on dopamine release in the rat.
abstract: It has been suggested that minor alkaloids in plants play a role in the biological and neuronal actions of nicotine. We hypothesized that these molecules modulate the effect of nicotine on the activity of central dopamine (DA) neurons, one of the main cellular targets in addiction to drugs. In this study the effect of a single intraperitoneal injection of either nicotine or an alkaloid extract of the tobacco plant (0.5 mg/kg) on the efflux of DA were investigated. DA was measured in vivo by intracerebral microdialysis in the nucleus accumbens and the striatum of freely-moving rats. Results show that nicotine enhanced accumbal and striatal DA extracellular levels (+47 and 20% above baseline, respectively). The extract also evoked a significant increase in DA extracellular levels in both regions (+33 and +38% above baseline). However, this effect was significantly higher compared to nicotine in the striatum only. In conclusion, the tobacco extract enhanced the neurochemical effect of nicotine alone in the striatum, a response that could underlie the higher propensity of developing addictive-like behavior using nicotine with tobacco alkaloids.
authors.affiliation: Laboratory of Pharmacology, Neurobiology and Behavior (URAC-37), University Cadi Ayyad, Faculty of Sciences Semlalia, Marrakesh, Morocco.
authors.forename: Hanane
authors.initials: H
authors.lastname: Khalki
authors.forename: Sylvia
authors.initials: S
authors.lastname: Navailles
authors.forename: Camille L
authors.initials: CL
authors.lastname: Piron
authors.forename: Philippe
authors.initials: P
authors.lastname: De Deurwaerdère
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis*; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009538:Nicotine / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014026:Nicotiana / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D010936:Plant Extracts; D009538:Nicotine; D004298:Dopamine