Nicotine-treated rats exhibited a marked reduction in body weight (Fig. 1A) associated with reduced food intake over 24 and 48 h of treatment (Fig. 1B). We evaluated whether the anorectic effect was a genuine action of nicotine or a secondary effect of the drug. It has been reported that nicotine induces RD in neonatal and anesthetized rats (29,30). Nicotine-treated rats showed a significant short-term RD after the injection (RD-vehicle–treated: nondetected; RD-nicotine–treated: 5.0 ± 1.4 min; P < 0.001). Ten minutes after nicotine administration just 5% of the rats showed symptoms of RD; 15 min after injection those symptoms were completely abolished (Fig. 1C). These data suggest that an effect of RD on 12-h feeding patterns is unlikely.
