Abstract
The convulsive movements, blood levels of corticosterone and pharmacokinetics of nicotine after an acute intraperitoneal injection of nicotine (5 mg/kg) were examined in young (6-week-old) and old (2-year-old) rats. In pharmacokinetic study, blood nicotine levels during the elimination phase were significantly higher in old rats than in young rats. However, the duration of convulsions and the elevation of corticosterone levels after the nicotine injection showed significant decreases in old rats compared with those in young rats. These differences of nicotine-induced responses between young and old rats may be involved in the decrease in nicotine sensitivity.
