title: Varenicline decreases nicotine but not alcohol self-administration in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats.
abstract: BACKGROUND
  Alcohol and nicotine are largely co-abused. Here, we investigated whether concurrent exposure to both addictive drugs influences each other's consumption and whether varenicline attenuates alcohol consumption in the presence of nicotine.
  
  
  METHODS
  Marchigian Sardinian alcohol-preferring (msP) rats trained to simultaneously self-administer oral alcohol (10% v/v) and intravenous nicotine (30μg/kg/inf) were used. Additional groups of rats were trained to self-administer either alcohol or nicotine. Further, msP rats were also trained to self-administer nicotine followed by 22-h/day access to alcohol and water in a two bottle free choice paradigm or water alone. The effects of varenicline (0.0, 0.3, 1.0, 3.0mg/kg, p.o.) on alcohol and nicotine consumption were tested.
  
  
  RESULTS
  In a self-administration paradigm, msP rats showed a significantly high level of alcohol and nicotine intake when the drugs were administered alone. However, when access to both drugs occurred concomitantly, the number of nicotine infusions self-administered was significantly decreased. Nicotine self-administration was markedly reduced by varenicline regardless of whether it was self-administered alone or concurrently with alcohol. In a two bottle choice test, varenicline significantly decreased nicotine self-administration but had no influence on alcohol consumption.
  
  
  CONCLUSIONS
  Varenicline is highly efficacious in decreasing nicotine self-administration either alone or in combination with alcohol. However, varenicline failed to influence both operant responding for alcohol and home-cage alcohol drinking in msP animals. Taken together, our findings suggest that the effects of varenicline could be specific to nicotine under conditions where excessive alcohol drinking is facilitated by genetic factors as in msP rats.
authors.affiliation: University of Camerino, School of Pharmacy, Pharmacology Unit, Camerino, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Scuppa
authors.affiliation: Torrey Pines Institute for Molecular Studies, Department of Neuropharmacology, Port St. Lucie, FL, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cippitelli
authors.affiliation: Torrey Pines Institute for Molecular Studies, Department of Neuropharmacology, Port St. Lucie, FL, USA.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Toll
authors.affiliation: University of Camerino, School of Pharmacy, Pharmacology Unit, Camerino, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ciccocioppo
authors.affiliation: University of Camerino, School of Pharmacy, Pharmacology Unit, Camerino, Italy. Electronic address: massimo.ubaldi@unicam.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Ubaldi
mesh_terms: D000428:Alcohol Drinking / Q000235:genetics; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000008:administration & dosage*; D002755:Choice Behavior / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000008:administration & dosage*; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D012646:Self Administration; D000068580:Varenicline / Q000494:pharmacology*
chemical_list: D002492:Central Nervous System Depressants; D018722:Nicotinic Agonists; D000431:Ethanol; D009538:Nicotine; D000068580:Varenicline
keywords: Addiction; Co-abuse; Drug-dependence; Ethanol; Tobacco smoking