TABLE 1

Plasma cotinine levels in nicotine-treated mice

Mice (>8 months old) were given 300 μg/ml nicotine in the drinking water. Blood was collected via the orbital sinus 1 week after treatment with 300 μg/ml nicotine or from the trunk during sacrifice. Plasma levels of cotinine, the primary metabolite of nicotine, were significantly increased in mice treated with nicotine. Plasma cotinine levels were not detectable in mice when treatment was stopped 18 h before blood collection. Values expressed as mean ± S.E.M. for the indicated number of animals.