Arginine-Vasotocin

Table 5.31. 13C Chemical Shifts (<5C in ppm) of Oxytocin, Arginine Vasotocin, Arginine, and Lysine Vasopressin in D20 [833],...

C Atom Oxytocin Arginine vasotocin Arginine vasopressin Lysine vasopressin... 

Vasopressin 8-arginine-vasopressin (AVP) Antidiuretic hormone (ADH) Lysipressin Oxytocin (OT) 8-leucine-vasotocin... 

Oxytocin, Lysin- und Arginin-Vasoprcssin, Arginin-Vasotocin. Adrenocorticotrope Hormone (Corticotropine, ACTH)... 

Hormones related to oxytocin and vasopressin occur in most vertebrates, the compound vasotocin shown in Fig. 30-4 being the most common. Substitution of phenylalanine for isoleucine at position 3 gives arginine vasopressin, the vasopressin found in our bodies. Structure of oxytocin and related hormones82 are also shown in Fig. 30-4. Like somatostatin, vasopressin and oxytocin may also form antiparallel pleated sheet structures with P turns. The structural requirements for hormone activity have been studied intensively. Both the macrocyclic hexapeptide ring and the tripeptide side chains are necessary for maximal activity.83... 

The inhibitory GTP binding protein (G ) which has been demonstrated in many different cell types is also present in Leydig cells. Evidence for this was obtained from studies with cultured Leydig cells in which it was shown that the inhibitory effects of arginine vasotocin on steroidogenesis could be abolished by pertussis toxin, which inactivates Gj via ADP ribosylation [9]. However, effects of LH with or without vasotocin were not reported. Similar studies with forskolin [10] demonstrated that low concentrations of this compound inhibited hCG-stimulated cyclic AMP production and this inhibition was prevented by pertussis toxin. Recently, direct evidence for the presence of Gj in rat Leydig cells has been obtained by the demonstration of a 41000 protein (aj) after [32P]ADP ribosylation [11]. 

These data show the presence in subesophageal and thoracic ganglia of Locusta of an antiparallel dimeric peptide (F2), which was called the AVP-like insect diuretic hormone (AVP-like DH) (H). The sequence homology between the AVP-like DH and the vertebrate neurohypophyseal peptides is strong Cys-(2)-(3)-(4)-Asn-Cys-Pro-(8)-Gly-NH2. The AVP-like DH and AVP differ only at positions 2, 3, and 4, whereas the homology to the ancestral molecule arginine vasotocin is even stronger, with differences restricted to positions 2 and... 

Various other substances have been shown to act as inhibitors of pituitary gonadotropic activity. These include synthetic arginine vasotocin (M13) and an extract prepared from the pineal gland of cattle (R14). 

M13. Moszkowska, A., and Ebels, I., A study of the antigonadotrophic action of synthetic arginine vasotocin. Experientia 24, 610-611 (1968). 

In the rough-skinned newt Taricha granulosa, arginine vasotocin (AVT) plays important roles in reproduction. It elicits oviposition in the female (Moore, Wood Boyd,... 

Moore, F.L. Miller, L.J. 1983. Arginine vasotocin induces sexual behavior of newts by acting on cells in the brain. Peptides, 4, 97-102. 

Toyoda, F., Yamamoto, K., Tanaka, S. Kikuyama, S. 1997. Possible involvement of arginine vasotocin in reproductive events of the male newt, Cynops pyrrhogaster. In Advances in Comparative Endocrinology (Ed. by S. Kawashima S. Kikuyama), pp365-369. Bolognia Monduzzi Editore. 

W.H. Sawyer, R.A. Munsick, H.B. van Dyke, Pharmacological evidence for the presence of arginine vasotocin and oxytocin in neurohypophysial extracts from cold-blooded vertebrates. Nature (Lond.) 184 1464-1465 (1959)... 

Schreibman, M. P., and Halpern, L. R., 1980, The demonstration of neurophy-sin and arginine vasotocin by immunocytochemical methods in the brain and pituitary gland of the platyfish, Xiphophorus maculatus, Gen. 

Figure 4.6. Effects of hypothalamic extracts, lysine vasopressin and arginine vasotocin on the...

There is no evidence that this observation has any physiological significance but, in this respect it is interesting to note that arginine vasotocin has been demonstrated in the pineal gland, cerebrospinal fluid and hypothalamus of certain mammalian species. However, as yet, no physiological role has been assigned to it. 

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