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)

We have assessed the influence of acute bilateral nephrectomy, of captopril and saralasin, on the hypotensive activity of neurotensin (NT) and of various hypotensive drugs in pentobarbital-anesthetized rats. The results show that the hypotensive activity of NT and of compound 48/80 (C48/80), in contrast to that of histamine, of 5-hydroxytryptamine and of hexamethonium, is markedly reduced, especially for NT, in nephrectomized as compared to sham operated rats. The pretreatment of rats with captopril (10 mg kg-1, i.v.) or with saralasin (20 micrograms kg-1 min-1, i.v.) was found to inhibit significantly the hypotensive activity of NT and of C48/80. Adrenalectomy restored partially the hypotensive activity of NT in nephrectomized rats. The potent vasopressin antagonist [d(CH2)5 Tyr(Me)AVP] did not alter the refractoriness of nephrectomized rats to the hypotensive activity of NT. Neither nephrectomy nor saralasin were found to interfere with the ability of NT or of C48/80 to evoke an increase of plasma histamine level or of the hematocrit. The results were interpreted as an indication that NT produces part of its hypotensive effect in anesthetized rats by reducing the activity of the renin angiotensin system. The results also suggest that part of the refractoriness of nephrectomized rats to the hypotensive activity of NT could be due to the release of catecholamines from adrenal glands by NT. Endogenous vasopressin does not appear to contribute to the refractoriness of nephrectomized rats to the hypotensive action of NT.
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PMID:Partial blockade of neurotensin-induced hypotension in rats by nephrectomy captopril and saralasin. Possible mechanisms. 619 Dec 40

Substance P(SP), the heptapeptide SP and the stable analogue (p-Glu5-MePhe8-MeGly9) SP (DiMe-C7) induce a Ca2+-dependent release of Met5-enkephalin (MET) from slices of periaqueductal gray matter (PAG) and striatum of rats. The MET release from striatal slices is greater than that from PAG slices because of the higher MET content of striatum. Intraventricular injection of SP and of the two related peptides induce analgesia in the rat, and their analgesic potency is in line with their capacity to release MET. Other neuropeptides which possess antinociceptive activity such as bombesin, neurotensin, vasopressin and somatostatin fail to release MET from PAG slices.
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PMID:Substance P-induced release of Met5-enkephalin from striatal and periaqueductal gray slices. 619 90

Immunohistochemical studies of the vas deferens and seminal vesicle of mouse, guinea-pig, and rabbit showed the presence of nerve fibres containing vasoactive intestinal polypeptide (VIP), substance P (SP), and gastrin-releasing peptide (GRP) supplying the smooth muscle layers as well as blood vessels. The nerve supply was better developed in the seminal vesicle than in the vas deferens. The motor activity of the vas deferens and seminal vesicle of the guinea-pig was studied in vitro. The vas deferens responded to transmural electrical stimulation with a twitch followed by a slow contraction. The twitch was blocked by guanethidine and tetrodotoxin, but not by atropine, propranolol, phenoxybenzamine, or fluphenazine. The slow contraction exhibited features of an alpha-receptor-mediated response. SP, physalaemin and eledoisin contracted the smooth muscle and also potentiated the twitch response to electrical nerve stimulation in a concentration-dependent manner. The SP blocking agent, (D-Pro2,D-Trp7,9)-SP, affected neither the resting tension nor the response to electrical stimulation. It is therefore suggested that the SP fibres act mainly prejunctionally. VIP, Leu-enkephalin, cholecystokinin octapeptide (CCK-8), angiotensin II, vasopressin, neurotensin, bombesin, and GRP had no effect on either the resting tension or the response to electrical nerve stimulation. The seminal vesicle responded to electrical stimulation with a contraction which was unimpaired by atropine, propranolol, phenoxybenzamine, and guanethidine, but abolished by tetrodotoxin. Hence, this contraction is mediated by a non-adrenergic, non-cholinergic neurotransmitter. Bombesin, GRP, SP, physalaemin and eledoisin contracted the smooth muscle and potentiated the response to electrical stimulation. VIP, Leu-enkephalin, CCK-8, angiotensin II, vasopressin, and neurotensin had no effect on the resting tension or on the response to transmural electrical stimulation. The SP antagonist abolished the contraction elicited by SP but did not influence the response to nerve stimulation. The results suggest that the SP and GRP nerves may have prejunctional and facilitating postjunctional effects in the seminal vesicle.
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PMID:Immunohistochemical localization of substance P, vasoactive intestinal polypeptide and gastrin-releasing peptide in vas deferens and seminal vesicle, and the effect of these and eight other neuropeptides on resting tension and neurally evoked contractile activity. 619 10

Primary cultures of neonatal murine brain have been reported to express multiple receptors that regulate adenylate cyclase activity. Since for the most part these results were obtained with mixed cell cultures, it has been difficult to define receptor profiles for specific cell types. With this concern in mind a series of studies has been initiated designed to identify specific receptors present on highly purified, immunocytochemically defined astroglia derived from the cerebral cortices of neonatal rats. In this study the capacity of a variety of peptide hormones to regulate cyclic AMP metabolism in these cells was examined. Fibroblasts derived from the meninges represent a predictable source of contamination in primary CNS culture. Thus, to assign more clearly specific receptors to the astroglial cell population, receptor-mediated regulation of cyclic AMP accumulation was also examined in fibroblasts. Cyclic AMP accumulation in astroglia was stimulated by catecholamines (acting at beta 1-adrenergic receptors), prostaglandin E1, vasoactive intestinal polypeptide, alpha-melanocyte-stimulating hormone, and adrenocorticotropin. Bombesin, luteinizing hormone-releasing hormone, neurotensin, thyrotropin-releasing hormone, somatostatin, secretin, and vasopressin did not significantly increase cyclic AMP levels in these cultures. Catecholamines, acting at alpha 2-adrenergic receptors, and somatostatin inhibited agonist-stimulated cyclic AMP accumulation. In meningeal cell cultures catecholamines (acting at beta 2- and alpha 2-adrenergic receptors) and prostaglandin E1 regulated cyclic AMP levels. However, vasoactive intestinal peptide did not stimulate and somatostatin did not inhibit cyclic AMP accumulation in these cells.
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PMID:Regulation of cyclic AMP accumulation by peptide hormone receptors in immunocytochemically defined astroglial cells. 620 41

125I-angiotensin II (125I-AII) binding was examined in the hypothalamic-thalamic-septal-midbrain (HTSM) region of HLA-Wistar rats in the presence of CNS-active agents. Angiotensin I, II, and III and saralasin competed for 125 I-AII binding, whereas structurally unrelated peptides such as arginine and lysine vasopressin, oxytocin, LHRH, TRH, bradykinin, and substance P did not. In contrast, ACTH and neurotensin exhibited a weak, dose-dependent competition for 125 I-AII binding. The relative potencies of AII, AI, neurotensin and ACTH were 100:1:0.1:0.05, respectively. Neurotensin and ACTH competition was not additive with AII suggesting interaction at shared binding sites. Most importantly, a wide variety of other CNS active agents such as methyldopa, naloxone, catecholamines, clondidine, and reserpine, failed to inhibit 125 I-AII binding, thus further defining the specificity of the CNS AII receptor.
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PMID:The specificity of angiotensin II receptor binding in rat brain. 627 72

The brain contains a large variety and number of peptides some of which were known earlier as hypothalamic hormones (vasopressin, oxytocin, luteinizing hormone-releasing hormone, thyrotropin-releasing hormone, somatostatin) or as pituitary hormones (the family of opiomelanocortins), while others, not primarily known as hypothalamic or pituitary hormones, may also have endocrine effects (substance P, angiotensin II, neurotensin, bombesin, vasoactive intestinal peptide (VIP), gastrin-cholecystokinin, glucagon, carnosine, bradykinin). These peptides, which form a new class of putative neurotransmitters, are present early in brain development and show important sex differences in both their pattern of innervation and their effects. Their peripheral effects may include intrauterine growth of the placenta and fetus, the timing of birth, acceleration of the course of labour and responses to haemorrhage (redistribution of cardiac output and stimulation of blood cell formation). Endogenous peptides are probably involved in brain development, which may explain their general, permanent and sex-dependent effects when given in the period of rapid brain development. Although peptides might in the future be useful for stimulating recovery from retarded brain development, at present one should be aware of the potential dangers of their use in, for example, obstetrics.
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PMID:Development of peptidergic systems in the rat brain. 627 64

Cultured endothelial cells derived from cerebral microvessels separated from 2-day-old rat brain contain a specific beta 2 and alpha 2-adrenergic sensitive adenylate cyclase (AC). Among the various tested hormones, PGE1 and PGE2 were found to be the most potent activators, while adenosine, angiotensin I and II, gamma-aminobutyric acid and vasoactive intestinal peptide inhibited the enzyme activity. However, acetylcholine, histamine, serotonin, glycine, glutamine, bradykinin, neurotensin and vasopressin (Lysine and Arginine) had no effect on the adenylate cyclase activity in this model. The susceptibility of the cerebrovascular endothelial AC system to the vasoactive substances as well as presence of beta 2 and alpha 2-type adrenergic receptors in the cultured endothelium provides additional support for the proposed endothelial involvement in the regulation of cerebrovascular permeability and blood flow.
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PMID:Cerebral endothelial cell culture. I. The presence of beta 2 and alpha 2-adrenergic receptors linked to adenylate cyclase activity. 627 96

A post-proline cleaving enzyme [prolyl endopeptidase, EC 3.4.21.26] was purified about 3,700-fold from an extract of bovine brain by a series of column chromatographies on DEAE-Sephadex, hydroxyapatite and PCMB-T-Sepharose, and gel filtration on Sephadex G-200 using N-carbobenzoxy-Gly-Pro-beta-naphthylamide (Z-Gly-Pro-2-NNap), thyrotropin releasing hormone (TRH) and oxytocin as substrates. The purified enzyme appeared homogeneous as judged by disc gel and SDS gel electrophoreses. The enzyme was most active at pH 7.5 and 7.2 with Z-Gly-Pro-2-NNap and TRH, respectively, and hydrolyzed peptide bonds involving Pro-X (X=amino acid, peptide, ester and amide) bonds of synthetic substrates, oxytocin, vasopressin, neurotensin, substance P, tuftsin, bradykinin, and insulin B chain. However, the enzyme was inert toward collagen, gelatin, and casein. The enzyme was completely inactivated by diisopropylphosphorofluoridate (DFP), Z-Gly-Pro-chloromethyl ketone and p-chloromercuribenzoate (PCMB), while it was not inhibited by phenylmethane sulfonylfluoride (PMSF) or metal chelators. Determination of the amino acid composition revealed that the enzyme contained 25 half-cystines. Modification of three cysteine residues of the enzyme by PCMB led to complete inactivation. The isoelectric point of the enzyme was 4.8, and the molecular weight was estimated to be 76,000 by ultracentrifugal analysis and 75,000-74,000 by both gel filtration and sodium dodecyl sulfate (SDS) gel electrophoresis, suggesting that the enzyme is present as a monomer. These results indicate that the post-proline cleaving enzyme from bovine brain is very similar to those previously purified from lamb brain and kidney in its enzymatic properties, substrate specificity and physicochemical properties, in sharp contrast with the results obtained by Tate, who reported that the bovine brain prolyl endopeptidase was inert toward oxytocin, vasopressin and bradykinin.
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PMID:Post-proline cleaving enzyme (prolyl endopeptidase) from bovine brain. 636 Oct 10

Isometric tension responses to neuropeptides were recorded from anococcygeus muscles isolated from male mice. This smooth muscle tissue is innervated by inhibitory nonadrenergic, noncholinergic nerves that resemble, ultrastructurally, the peptidergic neurons of the gastrointestinal tract; the physiological function of the anococcygeus is not known. Slow sustained contractions were produced by oxytocin (0.2-20 nM), [Arg8]vasopressin (0.4-200 nM), and [Arg]-vasotocin (0.4-100 nM); the mouse anococcygeus is, therefore, one of the few examples of nonvascular smooth muscle from male mammals to respond to low concentrations of oxytocin and related peptides. Substance P (0.5-8 microM) caused distinctive, biphasic increases in muscle tone of some, but not all, preparations. Other neuropeptides producing contractions were neurotensin (2-100 microM) and thyrotropin-releasing hormone (2-100 microM); the responses were of similar time course and displayed selective cross-desensitization, suggesting that these two peptides act through a common distinct mechanism. Tetradecapeptide somatostatin (10-80 microM) and its analog urotensin II (0.1-5 microM), a dodecapeptide from the urophysis of the teleost fish Gillichthys mirabilis, produced similar slowly developing relaxations of carbachol-induced tone. Piscine urotensin II, of which there are no reported effects on nonvascular mammalian systems, was 20-50 times more potent than somatostatin, a well-established mammalian hormone. Of the peptides studied, only vasoactive intestinal polypeptide (0.05-1 microM) caused rapid powerful relaxations in low concentrations; this is consistent with its proposed involvement in nonadrenergic, noncholinergic neurotransmission in the mouse anococcygeus.
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PMID:Neuropeptide-induced contraction and relaxation of the mouse anococcygeus muscle. 658 16

A number of neuropeptides have been found to affect fluid intake when injected directly into the brain of various vertebrate species. These include: angiotensin II and its peptide precursors; the tachykinins Substance P, eledoisin and physalaemin; the opioid peptides met- and leu-enkephalin and beta-endorphin; bombesin; neurotensin; and vasopressin. Some of these stimulate drinking, some inhibit water intake, and the tachykinins have opposite effects on thirst depending on the species tested. Very little is known about the site or mechamism of action of most of these peptides or if their effects on thirst are physiological. The exception is angiotensin II, a peptide hormone that is synthesized in the blood in response to hypovalaemia or hypotension and is involved in many aspects of the regulation of blood volume and pressure. Angiotensin II injected intravenously or intracranially stimulates drinking in all reptiles, birds and mammals tested. In addition to its role as a hormone, angiotensin II may also function as a neurotransmitter or neuromodulator, since all of the enzymes and precursors necessary for its synthesis have been found in the central nervous system.
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PMID:Neuropeptides and thirst. 658 33


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