AVIAN NEUROHYPOPHYSIAL HORMONES: PHARMACOLOGICAL PROPERTIES AND TENTATIVE IDENTIFICATION¹

Abstract

The pattern of pharmacological activities in the chicken ncurohypophysis has been studied and described. These activities correspond to those of a mixture of oxytocin and arginine vasotocin, an analogue of oxytocin synthesized by Katsoyannis and du Vigneaud. Paper chromatographic and enzymatic studies, together with the demonstration of inactivation by thioglycollatc, furnish additional evidence suggesting that oxytocin and arginine vasotocin may be neurohypophysial hormones in the chicken, Galhis domesticus. P RESSOR and diuretic responses to the intravenous injection of chickenposterior pituitary extracts were originally demonstrated by Herring in 1908 (1). Mackenzie (2) found that such extracts also had potent galactogogue (milk-ejection) activity. Antidiuretic and oxytocic activities in extracts of fowl posterior pituitaries were first demonstrated by de Lawder, Tarr and Geiling (3), and Geiling subsequently reported that these activities were about one-half as strong as those present in U.S.P. Posterior Pituitary Powder (4). Frog water-balance activity was first described in the bird pituitary by Heller (5). Water-balance activity was far greater than in mammalian extracts of equivalent oxytocic and antidiuretic potency.Detailed pharmacological and chemical studies of neurohypophysial hormones from vertebrates other than mammals have not been reported. In the present study we used manifold assays, chromatography and inactivation by trypsin and thioglycollate to characterize neurohypophysial hormones of the domestic chicken.

Preparation of oxytocin specifically 14C‐labeled in the tyrosine residue

“…1). The material exhibited an avian vasodepressor activity [26,27] of 463 -+ 11 U/mg*, a value comparable to that reported for *Concentration of the hormone was determined on the basis of specific radioactivity of the hormone and cpm/ml of solution. purified oxytocin [28,29].…”

Method for Correlation of Proton Magnetic Resonance Assignments in Different Solvents: Conformational Transition of Oxytocin and Lysine Vasopressin from Dimethylsulfoxide to Water

“…1) were prepared by the solid-phase method of peptide synthesis (11), and exhibited 450-500 U/mg of avian vasodepressor (12) and 270-300 U/mg of rat pressor (13) activities, respectively, which is in line with potencies previously described for these hormones (14). Stock solutions of each hormone (3% w/v) were prepared in both Me2SO and water, and were acidified with HCO (to pH 2.5 for oxytocin and to pH 4.2 for Lys-VP).…”

The Clearance of Neurohypophysial Hormones From the Circulation of Non‐mammalian Vertebrates

“…Table 1 shows that when chicken or toad plasma was incubated with arginine vasotocin for up to three hr at 42.50 or 26.50 C, no inactivation of the hormone could be demonstrated. (Munsick, Sawyer & van Dyke, 1960;Tanako & Nakajo, 1962;Gilbert & Lake, 1963) and has also been shown (Heller, Ferreri & Leathers, 1967) to affect the amphibian oviduct, it seemed worth while to investigate the fate of this hormone in both sexes. Table 2, however, shows that the half-lives of both arginine vasotocin and oxytocin were very similar in male and female birds or toads.…”