Nicotine (which we may here consider to be the active ingredient of that vast chemical complex known as tobacco-smoke) is properly regarded as a neurotropic drug, and it has been as aptly suggested that it be included in that more-recently-named category of "psychopharmacological agents"; yet it is paradoxical that many of the more important "somatic" effects of nicotine (and side-effects of smoking) are mediated through two very sensitive endocrine mechanisms, that of the adrenals and of the post-pituitary gland.82 But this is, after all, only a seeming paradox; for the nicotine-induced hormonal secretion of epinephrine and vasopressin, respectively, is in fact neurogenic; and nicotine ordinarily exerts its action on these glands, directly or reflexly, via their very sensitive nervous connections.
To give some illustration of the ubiquity of the pharmacological effects said by various authors—but not without occasional contradiction—to result, either in whole or in part, from nicotine-induced epinephrine
SILVETTE H, LARSON PS, HAAG HB. Action of Nicotine and Tobacco-Smoking on the Adrenal MedullaA Review. Arch Intern Med. 1961;107(6):915–931. doi:10.1001/archinte.1961.03620060115015