The ability of nicotine infusion to modulate plasma aldosterone levels in response to different stressors was investigated. Sprague-Dawley rats given nicotine (5 mg/kg/day) or saline for 14 days were subjected to stress. Baseline plasma aldosterone (86+/-17 pmol/l) was unaffected by nicotine. Aldosterone was significantly elevated by restraint (450+/-72 pmol/l) and especially with cold (1249+/-172 pmol/l) or immobilization (1779+/-247 pmol/l) stress. Nicotine infusion attenuated the rise in aldosterone with restraint and cold stress, but not immobilization. These results reveal that nicotine infusion can attenuate the aldosterone response, depending on the type of stress.