Plasma cotinine levels in rats receiving chronic nicotine Rats were administered nicotine in the drinking water or via minipump. Cotinine levels were measured in rat plasma 2 wks after the initiation of maintenance levels of nicotine in the drinking water or after minipump implantation. Values represent the mean ± S.E.M. of the indicated number of animals.
Regimen | Treatment | Nicotine | Number of Rats | Cotinine |
|---|---|---|---|---|
| ng/ml | ||||
| Drinking water | Saccharin | 0 | 10 | 0 ± 0 |
| Nicotine | 50 μg/ml | 9 | 987 ± 81 | |
| Nicotine | 25 μg/ml | 9 | 303 ± 23 | |
| Minipump | Vehicle | 0 | 12 | 0 ± 0 |
|
| Nicotine | 2 mg/kg/day | 10 | 336 ± 49 |