title: A rat model of cigarette smoke abuse liability.
abstract: We sought to develop a rat model of cigarette smoke exposure (CSE) that created cotinine serum levels comparable to those of smokers and induced conditioned place preference (CPP) suggestive of cigarette smoke abuse liability. Rats were exposed to sidestream cigarette smoke delivered  semicontinuously for 2 periods of 20 (group S20), 40 (group S40), or 60 (group S60) min daily for 12 wk. Serum cotinine concentration in blood samples was determined at 1 and 20 h after CSE. A biased (black versus white chamber) CPP paradigm was used. In the high CSE group (group S60), serum  cotinine at 1 h (250 to 300 ng/mL) was comparable to average cotinine levels reported for addicted smokers (around 300 ng/mL). Cotinine levels at 20 h after CSE were higher than the smoker-nonsmoker cut-off value (greater than 14 ng/mL) in all smoking groups, with the S60 group having  the highest levels. All rats preferred the black chamber to the white chamber during the preexposure CPP test. The time spent in the white chamber was increased compared with 0-wk values in group S40 at 8 wk, group S60 at 4 and 8 wk, and the control group at 4 and 8 wk but not at 12 wk; however,  the shift in CPP was significantly higher at 8 wk in group S60 compared with other groups. In conclusion, interrupted 2-h daily CSE for 8 wk induced serum cotinine levels in rats comparable to those of smokers and induced CPP suggestive of cigarette smoke abuse liability.
authors.affiliation: Laboratory of Experimental Surgery and Surgical Research, Democritus University of Thrace, Alexandroupolis, Greece. pipsil@med.duth.gr
authors.forename: Petros
authors.initials: P
authors.lastname: Ypsilantis
authors.forename: Maria
authors.initials: M
authors.lastname: Politou
authors.forename: Constantinos
authors.initials: C
authors.lastname: Anagnostopoulos
authors.forename: Alexandros
authors.initials: A
authors.lastname: Kortsaris
authors.forename: Constantinos
authors.initials: C
authors.lastname: Simopoulos
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003367:Cotinine / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D008297:Male; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D062789:Tobacco Products / Q000633:toxicity; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine