Neurophysin and neurohypophysial hormones

Abstract

Following the discovery of the pressor, oxytocic and antidiuretic effects of posterior pituitary extracts, about 50 years ago, there have been two opposing views: one held by Abel and his co-workers (Abel, Rouiller & Geiling 1923; Abel 1930), according to which the oxytocic, pressor and antidiuretic properties belong to a single substance, and that of Dudley (1919), who considered that these activities were due to different substances. The first conception led MacArthur (1931) and later van Dyke and his collaborators (van Dyke, Chow, Greep & Rothen 1942) to isolate an apparently pure protein which possessed the three activities in ratios resembling those found in crude extracts of the gland. The second concept led Kamm (Kamm et al . 1928) and later du Vigneaud (1952), Fromageot and his colleagues (Acher & Fromageot 1955) to purify two different active principles: the one, oxytocin possessing oxytocic and milk-ejecting properties, the other, vasopressin possessing the pressor and the antidiuretic activities. The problem therefore was to determine if the van Dyke protein was the true hormone, oxytocin and vasopressin being only degradation products which retain the activities or whether the two peptides were the natural hormones, the van Dyke protein being a kind of common precursor or a storage form.