Mecamylamine hcl

Mecamylamine HCl and (-)-nicotine hydrogen tartrate salt (Sigma-Aldrich, St. Louis, MO) were dissolved in physiological saline (Patterson Veterinary, Devens, MA), and the pH was adjusted to approximately neutral (pH ~ 7), as necessary. (-)-Nicotine free base (Sigma-Aldrich) was mixed with a 50:50 propylene glycol and glycerin solution (Sigma-Aldrich). Doses of nicotine for injection are expressed as mg/kg of the base. Nicotine and mecamylamine were injected subcutaneously (s.c.) at a volume of 10 ml/kg. Concentrations for aerosol administration are expressed as mg/ml in the e-cigarette tank, and may not be representative of the actual amount of nicotine inhaled.
Chemicals and reagents for the analysis of biological samples were purchased commercially and included nicotine (Sigma-Aldrich), cotinine (Toronto Research Chemicals, Toronto, ON), nicotine-d3 (Cambridge Isotope Laboratories, Tewksbury, MA), cotinine-d3 (Santa Cruz Biotechnology, Dallas, TX), ammonium acetate (Sigma-Aldrich), and formic acid and acetonitrile (Fisher Scientific, Fair Lawn, NJ). An internal standard solution was prepared in methanol (Fisher Scientific) containing 48 µg/mL nicotine-d3 and 38 μg/mL cotinine-d3. Working solutions containing both nicotine and cotinine were prepared in methanol at concentrations of 10,000 and 100 ng/mL.

(−)-Nicotine hydrogen tartrate [(−)-1-methyl-2-(3-pyridyl) pyrrolidine (+)-bitartrate] and mecamylamine HCl (non-selective nAChR antagonist) were purchased from Sigma-Aldrich Inc. (St. Louis, MO, USA). Varenicline (7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino(2,3-h)(3)benzazepine) was supplied by the National Institute of Drug Abuse (NIDA Drug Supply Program, Bethesda, MD). Drugs were dissolved in physiological saline and administered subcutaneously (s.c.) and freshly prepared solutions were given to mice at 10 ml/kg. All doses are expressed as the free base of the drug. All studies were conducted by an experimenter blinded to treatment.

(−)-Nicotine hydrogen tartrate [(−)-1-methyl-2-(3-pyridyl) pyrrolidine (+)-bitartrate] and mecamylamine HCl (non-selective nAChR antagonist) were purchased from Sigma-Aldrich Inc. (St. Louis, MO, USA). PNU120596 [1-(5-Chloro-2, 4-dimethoxy-phenyl)-3-(5-methyl-isoxazol-3-yl)] and PNU282987 [N-(3R)-1 Azabicyclo [2.2.2] oct-3-yl-4-chlorobenzamide] were obtained from the National Institute on Drug Abuse (NIDA) supply program (Bethesda, MD). NS1738 was purchased from Tocris Biosciences (Minneapolis, MN). Nicotine, mecamylamine, and PNU282987 were dissolved in physiological saline. NS1738 and PNU120596 were dissolved in a mixture of 1:1:18 [1 volume ethanol/1 volume Emulphor-620 (Rhone-Poulenc, Inc., Princeton, NJ) and 18 volumes distilled water]. Nicotine, PNU282987, and mecamylamine were injected subcutaneously (s.c.) while NS1738 and PNU120596 were administered intraperitoneally (i.p.). The nicotine solution pH was neutralized with sodium bicarbonate as needed. Freshly prepared solutions were given to mice at 10 ml/kg. Doses of nicotine and mecamylamine are expressed as the free base of the drugs.