title: Tobacco particulate matter self-administration in rats: differential effects of tobacco type.
abstract: Nicotine self-administration in rats is the most widely used animal model of tobacco dependence. There is increasing evidence, however, that non-nicotinic constituents in smoke contribute to addiction and that different tobacco products contain varying levels of these constituents. The present study firstly sought to compare self-administration of pure nicotine to tobacco particulate matter (TPM) to determine if there were differences in reward-efficacy attributable to the non-nicotine constituents. Secondly, cigarette and roll-your-own (RYO) TPM groups were included and compared to determine whether different formulations of non-nicotinic constituents could impact reward. Briefly, male Sprague Dawley rats were implanted with indwelling jugular catheters for self-administration (n = 76). The reinforcing efficacy of infusions of nicotine (0.0 or 30.0 μg/kg/infusion) versus cigarette/RYO TPM (with matched nicotine content) was determined using spontaneous acquisition of self-administration on a fixed ratio schedule. The progressive ratio schedule was then employed to determine the motivation to receive each drug and within-subject dose-response curves were also produced (7.5, 15.0, 30.0 and 60.0 μg/kg/infusion nicotine). The main finding was that the RYO TPM was more reinforcing and produced a different profile of reward-related behaviour compared with both the nicotine and the cigarette TPM groups. The conclusions were that non-nicotinic components have a role in tobacco dependence and that some tobacco products could have higher abuse liability, irrespective of nicotine levels.
authors.affiliation: School of Psychology, Victoria University of Wellington, Wellington, New Zealand.
authors.forename: Katharine A
authors.initials: KA
authors.lastname: Brennan
authors.forename: Alex
authors.initials: A
authors.lastname: Crowther
authors.forename: Fraser
authors.initials: F
authors.lastname: Putt
authors.forename: Vicky
authors.initials: V
authors.lastname: Roper
authors.forename: Uta
authors.initials: U
authors.lastname: Waterhouse
authors.forename: Penelope
authors.initials: P
authors.lastname: Truman
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004195:Disease Models, Animal; D058999:Drug-Seeking Behavior / Q000187:drug effects*; D008297:Male; D009042:Motivation / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D052638:Particulate Matter / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012201:Reward; D012646:Self Administration; D014029:Tobacco Use Disorder / Q000209:etiology*
chemical_list: D018722:Nicotinic Agonists; D052638:Particulate Matter; D009538:Nicotine
keywords: Cigarette; nicotine; roll-your-own; self-administration; tobacco dependence