Subcutaneous Administration of Nicotinic Compounds

The compounds (−)-nicotine bitartrate, (+/−)nornicotine, and (+/−)anabasine were obtained from Sigma Chemical Co. (St. Louis, MO, USA). The compound (+/−)anatabine was obtained from Toronto Research Chemicals, Inc. (North York, ON, Canada). All drugs were dissolved into sterile saline. The pH of all solutions was adjusted to 7.4 using dilute NaOH or HCl. All drugs were administered subcutaneously (sc) in a volume of 1 mL/kg. All drug doses are expressed as the base. The dose of each drug was as follows, nicotine: 0.50 mg/kg; nornicotine: 6.00 mg/kg; anatabine 3.00 mg/kg; anabasine 3.00 mg/kg. The doses selected were based on those used in our previous study evaluating the effects of the MTAs on deprivation-induced food intake [44 (link)]. The range of doses used in the previous investigation was narrowed down in the present study to a single dose of each drug that had previously produced reductions in food intake, without significant compensatory increases in food intake later in the day.