Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since iodination of the tyrosine residue in the pressin ring of vasopressins abolishes binding to the V2 (renal) isoreceptor, the low specific activity tritiated vasopressins have been the only radioligands available for this receptor. Alternative vasopressin radioligands are described in the present study. N-tert-Butoxycarbonyl- (N-t-Boc) 125I-tyrosine or [35S]methionine were conjugated to the 8th amino acid of lysine- (LVP) or deamino-ornithine-vasopressin via active succinimidyl esters. Following the purification on C-18 reverse-phase high pressure liquid chromatography, t-Boc removal, and a second high pressure liquid chromatography purification, specific activities of 2200 and 1300 Ci/mmol were obtained for the 125I- and the 35S-labeled ligands, respectively. These vasopressin analogues, conjugated outside the pressin ring, were found to bind with high affinity to the V1A (vascular) and V2 vasopressin isoreceptors (Kd less than or equal to 10(-9) M) and to retain the full biological activity of intact vasopressin. The present study demonstrates the possibility of producing high specific activity radioligands with high affinity for the V1A and V2 vasopressin isoreceptors by conjugating labeled moieties to the 8th amino acid of vasopressin analogues. Since these new radioligands have specific activities much higher than the tritiated ligands (1300-2200 versus 10-30 Ci/mmol), they should provide considerable advantages in the future study of the physiology and biochemistry of the AVP receptors.
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PMID:High specific activity 125I- and 35S-labeled vasopressin analogues with high affinity for the V1 and V2 vasopressin isoreceptors. 132 25

Mesangial cells respond to vasopressin by contraction and increased prostaglandin production. The purpose of the present study is to characterize vasopressin receptors from these cells. Glomeruli were isolated from rat kidneys and plated for explant growth of mesangial cells. Membranes were prepared from cells grown for 6 wk and tested for their ability to bind [3H]vasopressin (lysine vasopressin). These membranes contained a single class of specific vasopressin binding sites [equilibrium dissociation constant (Kd) = 10 +/- 1 nM, maximal binding capacity (Bmax) = 270 +/- 7 fmol/mg protein for 5 determinations]. Vasopressin induced a dose-dependent (apparent Kact value = 2 nM) accumulation of labeled inositol phosphates in myo[3H]inositol-prelabeled mesangial cells incubated in the presence of 10 mM of Li. Conversely, vasopressin failed to alter the adenylate cyclase activity of mesangial cell membranes. Competition experiments with a series of vasopressin structural analogues that have different degrees of affinity for V2-(renal), V1a- (vascular and hepatic), and V1b- (adenohypophyseal) receptors, indicated that vasopressin receptors from rat glomerular mesangial cells resemble the V1a- receptor subtype.
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PMID:Vasopressin receptors from cultured mesangial cells resemble V1a type. 295 5

Twelve L- and D-tyrosine-containing vasopressin analogues were prepared in their mono- and diiodinated forms. These include six arginine vasopressin (AVP) vascular (V1) type antagonists/antidiuretic (V2) agonists, four V1/V2 antagonists, and two V1/V2 agonists, one of which is AVP itself. Ten peptides were iodinated on the tyrosyl residue in position 2; two were iodinated on a tyrosyl amide residue replacing the glycyl amide residue at position 9. All peptides were tested both for their biological activities in vivo (rat vasopressor and antidiuretic tests) and for their ability to bind to vasopressin receptors of the V1 (vascular) and V2 (renal) types from rat liver and rat kidney membranes, respectively. It is shown that monoiodination of the tyrosyl residue in the vasopressin analogues that were tested either preserves or reduces to a highly variable extent the in vivo and in vitro biological activities of these analogues. In most cases diiodonitation resulted in a marked decrease in biological activity. The effects of iodination on the affinity of vasopressin analogues for hepatic V1 receptors and renal V2 receptors were more related to the affinity of the noniodinated peptide for these receptors than to the biological properties (antagonist versus agonist) of the tested analogues, the nature (L versus D) of the iodinated tyrosyl residue, or the position (2 versus 9) at which this residue was introduced. The loss of affinity due to iodination was usually more pronounced for peptides exhibiting high affinity for vasopressin receptors. However, we show that among the monoiodinated peptides some (especially monoiodinated [2-D-Tyrosine]-AVP) retained enough affinity for vasopressin binding sites to suggest that their radioiodinated conterparts would be promising labeled ligands for use in studies in vasopressin receptors.
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PMID:Iodination of vasopressin analogues with agonistic and antagonistic properties: effects on biological properties and affinity for vascular and renal vasopressin receptors. 295 51

Suspensions of rat anterior pituitary cells were exposed to corticotropin-releasing factor (CRF) (5 nM) and various neurohormones (0.002-1000 nM). CRF-induced secretion of ACTH was doubled by 0.1 nM arginine vasopressin (AVP), 0.2 nM arginine vasotocin, 1 nM oxytocin, 10 nM angiotensin II, and 100 nM noradrenalin; vasoactive intestinal peptide had no effect at 0.2-200 nM. CRF potentiation by AVP was also observed at lower concentrations of CRF. Since AVP appeared to be the most potent modulator of CRF-induced ACTH secretion, potentiation was further tested with specific antidiuretic and oxytocic agonists. Potentiation was clearly related to pressor biological activity, less so to antidiuretic, and hardly at all to oxytocic activities. However, even at 200 nM, the antipressor antagonists dPTyr(Me)AVP and d(CH2)5Tyr(Me)AVP had no effect on potentiation by AVP. The lack of antagonism was partly due to the agonistic effects of the antagonists on the pituitary gland, an effect not observed within vascular tissue. The results thus suggest that anterior pituitary vasopressin receptors resemble, but are not identical to, V1 (pressor and hepatic), do not resemble the V2 (renal), and might be classified as V3 (pituitary) receptors.
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PMID:A novel type of vasopressin receptor on anterior pituitary corticotrophs? 298 63

The ligand specificity of rat adenohypophyseal vasopressin receptors was directly compared to that of peripheral receptors of the V1 and V2 types. For this purpose a series of 15 recently designed vasopressin antagonists was used. The affinities of these antagonists for rat adenohypophyseal membranes were deduced from the determination of the concentration-dependent inhibition of [3H]vasopressin binding. In parallel experiments the corticotropin (or anti-corticotropin)-releasing activities of the tested peptides were determined on freshly dispersed rat adenohypophyseal cells. All peptides tested which were found to be antagonists of the vasopressor and antidiuretic responses to vasopressin in vivo behaved as antagonists of vasopressin-induced corticotropin release. There was a close correlation between the relative affinities of the analogues tested for binding to adenohypophyseal membranes and their relative potencies in inhibiting vasopressin-induced corticotropin release, indicating that the detected vasopressin-binding sites are the receptors involved in the vasopressin effect on corticotropin secretion. No correlation could be demonstrated between anti-corticotropin-releasing activities and either anti-antidiuretic or antivasopressor potencies of the antagonists tested. A direct comparison of the ligand specificities of adenohypophyseal receptors on the one hand, and V1 (hepatic) and V2 (renal) receptors on the other hand, showed that most of the antagonists discriminated very efficiently between adenohypophyseal and either hepatic or renal receptors. The selectivity index reaches values as high as 260,000 for desGly(NH2)9 [1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic acid), 2-D-O-ethyl-tyrosine, 4-valine] arginine vasopressin. It is concluded that adenohypophyseal receptors represent a novel type of vasopressin receptors. Based on the observation that adenohypophyseal receptors, like hepatic or vascular V1 receptors, do not appear to be coupled to adenylate cyclase, we propose that adenohypophyseal receptors could be designated as V1b receptors as opposed to the V1a receptors previously characterized on liver and blood vessels.
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PMID:Vasopressin antagonists allow demonstration of a novel type of vasopressin receptor in the rat adenohypophysis. 301

The effect of antiserum raised against rat urinary (renal) hyaluronidase has been examined in rats subjected to antidiuretic stimuli (water-deprivation or vasopressin infusion). Prior administration of antiserum abolishes the reduction in medullary and papillary extractable hexosamine which normally accompanies antidiuresis. Antiserum against rat testicular hyaluronidase was found to be without effect during water-deprivation. Water-loading significantly increased the level of extractable hexosamine. The findings are considered in relation to previous observations on the effects of antisera on renal and urinary composition and collecting duct morphology under identical experimental conditions. It is suggested that a functional relationship exists between the net degradation of medullary mucopolysaccharides by hyaluronidase and the concentrating capacity of the kidney.
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PMID:Renal medullary hexosamine content following antidiuresis and water-loading in the rat. Effects of antisera against rat urinary and testicular hyaluronidase. 719 63

An investigation has been carried out into the formation of dilated lateral intercellular spaces in the medullary collecting duct of the rat kidney following water deprivation or infusion of vasopressin. Dilation is conspicuous under these conditions, by comparison with normally hydrated controls, but its appearance is prevented by prior treatment of rats with antiserum raised against urinary (renal) hyaluronidase. Antiserum against testicular hyaluronidase is without effect. The presence or absence of dilatations in the lateral intercellular space correlates closely with previous findings on the ability or inability of rats to concentrate their urine under identical experimental conditions. It is concluded that urinary (renal) hyaluronidase plays an important role in the formation of such dilatations and that these facilitate the process of urinary concentration.
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PMID:The effect of antidiuretic stimuli on the morphology of the lateral intercellular spaces in the medullary collecting duct of the rat. 733 49

The oxytocin and the vasopressin V1a, V1b and V2 receptors have recently been cloned and shown to form a sub-family within the large superfamily of G-protein-linked receptors. Renal V2 receptors mediate vasopressin-induced water reabsorption via induction of intracellular cAMP production in collecting duct cells. Most remaining actions of vasopressin on blood vessel constriction, liver glycogenolysis, platelet adhesion, adrenal angiotensin II secretion and certain brain functions are mediated via v1a-type receptors that are coupled to a Gq/11 protein. V1 receptor activation leads to stimulation of phospholipases C, D and A2 and an increase in intracellular calcium. Vasopressin stimulates pituitary corticotrophin release via a third vasopressin receptor type (V1b) which is present on corticotrophs. Oxytocin induces myometrial contraction, endometrial prostaglandin F2 alpha production, mammary gland milk ejection, renal natriuresis and specific sexual, affiliative and maternal behaviours via oxytocin receptors which are also coupled to a Gq/11 protein. Although only one oxytocin receptor type has been cloned so far, recent binding studies indicate that uterine endometrial oxytocin receptors may constitute a distinct receptor subtype. In contrast to most other membrane receptors, the expression of oxytocin receptors undergoes very rapid and physiologically relevant up-and-down-regulation. A > 100-fold up-regulation of uterine oxytocin receptors occurs during gestation and may represent the trigger for parturition. Indeed, oxytocin receptor antagonists are able to counteract preterm labour and may soon be available for clinical use. The presence of oxytocin receptors on breast cancer cells and the growth-inhibitory effects of OT suggest a potential use of oxytocin analogues for breast cancer treatment. Whereas no mutations of the oxytocin or V1a or V1b receptors have been found, over 60 different genetic mutations of the (renal) V2 receptor have been described which represent the cause for congenital nephrogenic diabetes insipidus.
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PMID:Vasopressin and oxytocin receptors. 873 52

The neurohypophyseal peptides arginine vasopressin (AVP) and oxytocin (OT) mediate a wide variety of peripheral and central physiological and behavioral effects by acting on four different G-protein coupled receptors, termed V1a (vascular), V1b (pituitary), V2 (renal), and OT (uterine). We recently reported that d[Cha4]AVP (A), d[Leu4]AVP (B), d[Orn4]AVP (C), and d[Arg4]AVP (D) have high affinity and are selective agonists for the human V1b receptor. However, peptides A-D were subsequently shown to be potent antidiuretic agonists in the rat and are, thus, not selective V1b agonists in the rat. Peptides A-D served as leads for the studies reported here. They were modified at position 8 by Lys, ornithine (Orn), diaminobutyric acid (Dab), and diaminopropionic acid (Dap) to give d[Cha4,Lys8]VP (1), d[Cha4,Orn8]VP (2), d[Cha4,Dab8]VP (3), d[Cha4,Dap8]VP (4), d[Leu4,Lys8]VP (5), d[Leu4,Orn8]VP (6), d[Leu4,Dab8]VP (7), d[Leu4,Dap8]VP (8), d[Orn4,Lys8]VP (9), d[Orn4,Orn8]VP (10), d[Arg4,Lys8]VP (11), d[Arg4,Orn8]VP (12), and d[Arg4,Dab8]VP (13). All peptides were synthesized by the Merrifield solid-phase method. Their binding and functional properties were evaluated in rat AVP V1a, V1b, and V2 receptors and on the rat OT receptor expressed either in native tissues or in stably transfected cells. They were also examined in rat vasopressor, antidiuretic, and in in vitro (no Mg++) oxytocic assays. Functional studies performed on chinese hamster ovary cells expressing the different AVP/OT receptors confirm that d[Cha4,Lys8]VP (1), d[Cha4,Dab8]VP (3), d[Leu4,Lys8]VP (5), and d[Leu4,Dap8]VP (8) are the first selective agonists for the rat V1b receptor. These selective V1b agonists are promising new tools for studies of the role of the V1b receptor in the rat.
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PMID:Design and synthesis of the first selective agonists for the rat vasopressin V(1b) receptor: based on modifications of deamino-[Cys1]arginine vasopressin at positions 4 and 8. 1730 Jan 66

Oxytocin (OT) and vasopressin (AVP) mediate their biological actions by acting on four known receptors: The OT (uterine) and the AVP V(1a) (vasopressor), V(1b) (pituitary), V(2) (renal) receptors and a fifth putative AVP V(1c)? (vasodilating) receptor. This presentation will summarize some highlights of the recent progress, in the design and synthesis of selective peptide agonists, antagonists, radioiodinated ligands, fluorescent ligands and bivalent ligands for these receptors. Here we present published and unpublished pharmacological data on the most widely used agonists, antagonists and labelled ligands. The pharmacological properties of promising new selective OT antagonists and V(1b) agonists are also presented. This review should serve as a useful guide for the selection of the most appropriate ligand for a given study. The current status of non-peptide OT and AVP antagonists and agonists is also summarized. The relative merits of peptide and non-peptide AVP and OT agonists and antagonists as: (1) research tools and (2) therapeutic agents will be evaluated. Many of the receptor selective peptide agonists and antagonists from this and other laboratories are far more widely used as pharmacological tools for studies on the peripheral and central effects of OT and AVP than their non-peptide counterparts. In addition to OT and to a lesser extent AVP (pitressin), a number of OT and AVP analogues; such as carbetocin (OT agonist) dDAVP (desmopressin, V(2) agonist), terlipressin (V(1a) agonist), felypressin (V(1a) agonist) and atosiban (Tractocile OT antagonist) are also in clinical use. Despite much early promise, no non-peptide V(1a) or OT antagonists are currently in clinical trials. While a number of orally active non-peptide V(2) antagonists (Vaptans); notably, Tolvaptan, Lixivaptan and Satavaptan, are currently in Phase III clinical trials; to date, only the mixed V(2)/V(1a), antagonist Conivaptan (Vaprisol), has been approved by the US FDA for clinical use (by i.v. administration), for the treatment of euvolemic and hypervolemic hyponatremia in hospitalized patients. Promising new non-peptide V(1b) and OT antagonists, as well as non-peptide V(2) and OT agonists are now in pre-clinical development.
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PMID:Peptide and non-peptide agonists and antagonists for the vasopressin and oxytocin V1a, V1b, V2 and OT receptors: research tools and potential therapeutic agents. 1865 3


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