Fig. 1.

Effect of cytisine on epinephrine release and adrenal tyrosine hydroxylase (TH) mRNA levels: dose response. Experimental groups are as follows: Sal (saline-injected animals), 0.3 Cyt (animals injected ip with 0.3 mg/kg cytisine), 1 Cyt (1 mg/kg cytisine), 3 Cyt (3 mg/kg cytisine), and Nic (1 mg/kg nicotine). Each dose/drug was given twice daily, for a total of 7 episodes, to mimic the HAAF protocol. On day 4 the catheters were extended out of the cages, and arterial blood samples were collected stress free before and every 30 min after the last drug application (iv) for a total of 2 h. A: the results (plasma epinephrine values) are from 2 independent experiments (n = 6) and are presented as means ± SE. *P ≤ 0.05, Cyt vs. Sal; **P ≤ 0.002, Nic vs. Cyt. B: for RNA analyses, animals were euthanized 5 h after treatment and changes in adrenal medullary TH gene expression analyzed by Northern blots.