In analogy with the suprarenal gland and the pancreas, the pituitary gland contains two portions that differ absolutely in function and in pharmacology. It is remarkable that the parts of the suprarenal and pituitary that are most important to life have the least pharmacologic actions, while those parts whose extracts produce very striking pharmacologic effects—the suprarenal medulla and the posterior pituitary—appear to be of minor importance to the organism.
RESPONSE OF SMOOTH MUSCLE
Extracts of the posterior pituitary cause powerful stimulation of smooth muscle, varying in degree, however, in different situations and under different conditions; there may even be relaxation, or a sequence of relaxation and contraction. The effects occur in denervated organs. The peculiarities are not related to the origin of the autonomic innervation; the actions are therefore more closely related to those of histamin or the protein "shock" poisons, than to those of epinephrin.
RESPONSES OF THE UTERUS
SOLLMANN TH. GLANDULAR THERAPYPHARMACOLOGY OF THE PITUITARY GLAND. JAMA. 1924;83(21):1683–1684. doi:10.1001/jama.1924.26610210003014