Table 2

Chronic nicotine treatment is associated with long-term, sustained stimulation of TH gene transcription rate in rat adrenal medulla

Repeated Injections	Last Injection	Time after Last Injection	Relative TH Gene Transcription Rate (TH/28S) × 1000
Saline	Saline (15)	20 min	12 ± 2
Saline	Nicotine (12)	20 min	55 ± 8^2-a
Saline	Saline (5)	24 h	15 ± 2
Saline	Nicotine (4)	24 h	12 ± 4
Nicotine	Saline (11)	20 min	36 ± 4^2-a
Nicotine	Nicotine (11)	20 min	64 ± 5^2-a
Nicotine	Nicotine (6)	12 h	47 ± 7^2-a
Nicotine	Nicotine (7)	24 h	47 ± 10^2-a
Nicotine	Nicotine (7)	2 days	28 ± 4^2-a
Nicotine	Nicotine (6)	3 days	28 ± 4^2-a
Nicotine	Nicotine (5)	7 days	36 ± 7^2-a

Rats were injected twice daily for 7 days with either saline or 1.6 mg/kg nicotine. A final challenge injection of either saline or nicotine was administered on the morning of the 8th day, and the rats were euthanized at the time point designated in the table. Adrenal medullae were dissected, and TH gene transcription rate was measured using nuclear run-on assays. The data represent the means ± S.E. from the number of rats in parentheses.

↵2-a P < 0.01 compared with saline-treated controls.