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)

Analogs of [arginine8]vasopressin (AVP) in which the peptide chain was elongated from the N-terminus by the addition of Ala-Arg-Arg-, Ala-Ala-Phe-, Pro-Arg-Val-, Pro-Ala-Arg-Arg, and Pro-Ala-Ala-Phe-, and from the C-terminus by the addition of -Ala-Met-Ala-NH2 and -Gly-Arg-Arg-Ala-NH2 were synthesized by the solid phase method and purified by Sephadex G-15 chromatography. At the final step of the synthesis, the extent of formation of the intramolecular disulfide bond was found to be sequence dependent. These peptides were incubated with extracts of the rat hypothalamus (supraoptic region) and neural lobe and with isolated neurosecretory granules from the neural lobe, and the release of vasopressin was measured by the rat pressor assay. All peptides resisted conversion to the hormone in the presence of tissue extracts, except (Ala-Ala-Phe)-AVP which was converted to AVP in the presence of all three tissue extracts at pH 4.7 but not at pH 8.0. When these peptides were treated with trypsin, chymotrypsin, or leucine aminopeptidase at pH 8.0, only the action of chymotrypsin on [Ala-Ala-Phe]AVP resulted in AVP formation. Evidence obtained using lysosomal enzyme markers suggested that the converting enzyme activity in neurosecretory granule preparations was not of lysosomal origin.
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PMID:Extended chain analogs of [arginine8]vasopressin as model prohormones: investigation of precursor-processing enzymes in extracts of the rat hypothalamus and neural lobe. 675 99

The aim of the present study was to determine the magnitude and direction of the shift of body fluids during water immersion of humans to the neck. Five healthy male subjects were studied lying in air for 1.5 h, sitting in 34 degrees C water to the neck for 1 h, and again lying in air for 1.5 h in two sets of experiments. For the first set, vasopressin (0.75 IU, sc) was injected before immersion. Blood and urine samples were drawn every 30 min in air and every 20 min in water. Urinary sodium, potassium, and osmolal clearances were significantly increased during immersion. When the mean maximum change during immersion was calculated for five subjects hematocrit fell by 1.1 U, plasma concentrations of sodium by 3.9 meq/l, chloride by 3.5 meq/l, potassium by 0.2 meq/l, osmolality by 7.9 mosmol/kg H2O, and proteins by 0.25 g/100 ml, whereas total plasma CO2 content increased by 1.33 mmol/l, threonine by 11.6%, proline by 9.0%, methionine by 14.0%, and alanine by 29%. Plasma volume increased 6.1%, and red blood cell volume calculated from hematocrit and hemoglobin increased 3.5%. In the second set of immersion experiments, without vasopressin injection, interstitial fluid pressures were measured with a cotton wick in PE-50 tubing inserted subcutaneously. A mean interstitial fluid pressure of -0.5 cmH2O was observed when the subjects were lying in air. Interstitial fluid pressure had started to decrease by 20 min of immersion, with a maximum decrease during immersion averaging 2.10 cmH2O. We conclude that hyposmotic fluid is mobilized into the blood from interstitial and other extravascular spaces during immersion.
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PMID:Osmoregulation and interstitial fluid pressure changes in humans during water immersion. 679 64

Localization of enkephalins and opiate binding sites in the central nervous system of rats has been reported by several authors. These studies did not reveal an extensive enkephalinergic system in the hypothalamo-hypophyseal axis of rats. The present paper reports on an extensive enkephalinergic system in the cat hypothalamo-hypophyseal system. Sections of paraformaldehyde fixed cat hypothalami were incubated with anti-methionine enkephalin serum, anti-vasopressin serum, and anti-oxytocin serum. Immunohistochemical localization of methionine enkephalin fibers and terminals in the median eminence, hypophyseal stalk, and pars nervosa was similar, but not identical to the distribution of vasopressin and oxytocin in these structures. Neuronal perikarya localized with the three antisera in the nucleus supraopticus and nucleus paraventricularis were of a similar size and morphology. In cats treated with colchicine prior to sacrifice, the anti-methionine enkephalin serum revealed a group of periventricular cell bodies. Cell bodies were not localized in this area with anti-vasopressin or anti-oxytocin sera. The functional significance of such an extensive enkephalinergic system in the cat hypothalamo-hypophyseal axis is discussed.
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PMID:Relationship between enkephalinergic neurons and the vasopressin-oxytocin neuroendocrine system of the cat: an immunohistochemical study. 699 53

Evidence is accumulating that opiates inhibit the release of oxytocin and vasopressin by acting on nerve terminals in the neurohypophysis. Extracts of neurohypophysis have been shown to contain substantial amounts of Met- and Leu-enkephalin, and Leu-enkephalin-immunoreactive (IR) nerve fibres originating in the magnocellular hypothalamic nuclei have been described in the neural lobe, where the two hormones are secreted. We have compared the distribution of oxytocin, vasopressin and enkephalin immunoreactivity (IR) in the neurohypophysis of the rat, and report here that Met-enkephalin-IR is invariably associated with nerve terminals that contain oxytocin-IR whereas the terminals that contain vasopressin-IR often, but not invariably, are Leu-enkephalin immunoreactive.
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PMID:Enkephalins co-exist with oxytocin and vasopressin in nerve terminals of rat neurohypophysis. 700 86

The chemical structure of the hormone binding region of the neurophysins has been investigated by photoaffinity labeling with the photolabile tripeptide, L-[methyl-3H]Met-L-Tyr-p-azido-L-Phe amide. Photolysis of the photoaffinity tripeptide in the presence of bovine neurophysin I and II and a human neurophysin II led to approximately equal extents of covalent incorporation of radioactivity into protein. Photolabeled bovine neurophysin II was fractionated into binding site derivatized protein and nonbinding site derivatized protein by affinity chromatography, with results of amino acid and radiolabel analysis of the hormone binding site blocked protein indicating that 1 mol of tripeptide was covalently incorporated/mol of protein. Tyrosine 49 was the only protein amino acid modified in the binding site photolabeling reaction as assessed by peptide mapping of the performic acid oxidized and trypsin-digested photolabeled protein using reverse phase high performance liquid chromatography. Modification of the single neurophysin tyrosine also was found by amino acid analysis of performic acid oxidized photolabeled bovine neurophysin II. The covalent bond formed in neurophysin upon photolysis was cleaved by either exhaustive acid hydrolysis or reduction-carboxymethylation without loss of the protein amino acid residues and by performic acid oxidation with loss of both protein and tripeptide tyrosine residues. These overall data indicate that tyrosine 49 is the probable site for specific covalent attachment of the photoaffinity tripeptide. Assuming that the tripeptide binding site is the high affinity hormone binding site reported for the neurophysins, this conclusion argues that tyrosine 49 is close to or within this site.
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PMID:Photoaffinity labeling of the hormone binding site of neurophysin. 706 22

The reciprocal modulation of neurophysin self-association and noncovalent peptide--protein interaction between neurophysin and the hormones oxytocin and vasopressin has been assessed by quantitative affinity chromatography. Competitive elutions of radiolabeled bovine neurophysin II (NPII) from the affinity matrices Met-Tyr-Phe-omega-(amino-hexyl)- [and (aminobutyl)-] agarose were performed with increasing concentrations of either of the soluble ligands oxytocin or lysine-vasopressin. Also, the dependence of NPII retardation by the same adsorbents on the concentration of applied protein was investigated in the absence of soluble ligand. The affinity constant of NPII for the immobilized peptide increased markedly with increasing amounts of applied protein and with the addition of small amounts of soluble ligand, the latter being more pronounced at higher protein concentrations. The affinity constant of the protein for the soluble ligand showed a smaller increase. The variation of l/(V - V0) (where V = the NPII elution volume and V0 = the elution volume of noninteracting control protein) with soluble ligand concentration was linear except near [ligand] = 0. The quantitative affinity chromatographic results on the tripeptidyl affinity columns are consistent with the view that NPII exists in a monomer in equilibrium dimer equilibrium, with the dimer exhibiting a stronger interaction with both neuropeptide and tripeptide analogues. The data also indicate that the self-associated protein dimer itself exhibits cooperativity, that is, stronger binding of the immobilized ligand at one site when a second site is occupied with a molecule of the soluble ligand than when no soluble ligand is bound. The deduction from the above of ligand-induced dimerization is evident also in the increased retardation of NPII on neurophysin--Sepharose when the eluting buffer contains soluble peptide hormone.
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PMID:Interdependence of neurophysin self-association and neuropeptide hormone binding as expressed by quantitative affinity chromatography. 708 36

Metkephamid acetate, a newly synthetized analogue of methionine enkephalin, suppressed plasma vasopressin levels from 2.4 pg/ml to 0.8 pg/ml after intramuscular administration to 4 normal human volunteers. This suppression occurred in the absence of significant changes in either plasma osmolality or blood pressure. Thus, metkephamid acetate, like many other opiates which bind to the mu subtype of opiate receptors, has a direct suppressive effect on plasma vasopressin levels.
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PMID:A new Met-enkephalin analogue suppresses plasma vasopressin in man. 709 85

Limited tryptic fragmentation of disulfide-intact bovine neurophysins I and II (NP-I and -II, respectively) has been found to cause selective disruption of both hormone binding and neurophysin self-association. Loss of binding interactions, measured as a loss of ability to stimulate retardation of 125I-labeled neurophysin on Met-Tyr-Phe-amino-butylaminoagarose, is complete within 3 h at 37 degrees C. Reverse-phase high-performance liquid chromatography (HPLC) analysis of tryptic digests of neurophysin I allows detection of two major protein products and the peptide fragment 1-8. Release of the latter N-terminal piece occurs at about the same rate as loss of binding interactions. Reverse-phase HPLC elution behavior before and after performic acid oxidation and amino acid composition of the protein products led to their identification as NP-I-(9-93) (the 9-93 sequence) and [des-19,20]NP-I-(9-93) (the 9-93 sequence with the dipeptide 19-20 missing) for the more rapidly and more slowly formed species, respectively. NP-I-(9-93), unlike intact neurophysin I, is not retarded strongly by either Met-Tyr-Phe-amino-butylaminoagarose or neurophysin II-Sepharose. In contrast, both NP-I-(9-93) and [des-19,20]NP-I-(9-93) are equally as effective as intact NP-I in binding neurophysin I antibodies. The role of amino-terminal residues in promoting hormone binding, self-association, and antigenic recognition interactions is considered.
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PMID:Effects of limited tryptic proteolysis of bovine neurophysins on molecular properties of hormone binding, self-association, and antigenicity. 715 May 67

The effects of injection of a peptidase-resistant analog of methionine-enkephalin, [D-ala2]-methionine-enkephalin, on blood pressure (BP), heart rate, and vasopressin release were studied in spontaneously hypertensive rats (SHR). Intravenous injection of [D-Ala2]-methionine-enkephalin (DAME) increased BP in both SHR and normotensive Wistar-Kyoto (WKY) controls, with a significantly greater increase in hypertensive rats. Intracerebroventricular injection of DAME produced a biphasic increase in BP and an increase in heart rate in both groups. The initial pressor effect was significantly greater in the SHR, Plasma vasopressin levels in SHR were depressed relative to both untreated hypertensive rats and animals given vehicle control injections. Intravenous pretreatment with a vasopressin vasopressor antagonist, [l-(beta-mercapto-beta-beta-cyclopentamethylenepropionic acid),2-(O-methyl)tyrosine] arginine-vasopressin, did not block either component of the central enkephalin response in hypertensive rats. These date indicate that central enkephalin injection does not release vasopressin and that SHR are hyperresponsive to enkephalin. It is concluded that pressor systems other than that of vasopressin mediate the enkephalin-induced cardiovascular effects.
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PMID:Vasopressin release does not contribute to pressor action of enkephalin in SHR. 730 4

Methionine-enkephalin-like substance was measured in CSF by the radioreceptor-assay established by Furui et al. Samples were obtained from preoperative 20 cases, in which were included 11 cases of pituitary adenoma, 3 cases of craniopharyngioma, 2 cases of pseudtumor cerebri and 4 normal cases, by lumbar puncture. Also postoperative measurement of this substance and pre- and postoperative measurement of ACTH in plasma were performed in 5 cases of Cushing's disease. Five ml of CSF was chromatograpied on two successive columns, lyophilized and assayed for opiate receptor affinity against 3H-dihydromorphine. Measured values were expressed as methionine-enkaphalin equivalents using the displacement curve run in parellel. Methionine-enkephalin-like substance level ranged from less than 0.5 to 20.0 pmoles/ml in all cases and mean value was 2.6 pmoles/ml (+/- 1.0 S.E.) in normal subjects. In Cushing's disease the level was not elevated preoperatively (2.1 +/- 0.3) and did not significantly decrease postoperatively (1.6 +/- 0.4 pmoles/ml) in contrast to the decrease of ACTH in plasma. It is suggested that methionine-enkephalin-like substance in CSF is not derived from ACTH producing cells of pituitary gland. One case of craniopharyngioma showed very high value. This case revealed diabetes insipidus at sampling. The possibility of participation of methionine-enkephalin in secretion of antidiuretic hormone was discussed.
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PMID:[Measurement of methionine-enkephalin-like substance in CSF from normal subjects and patients with pituitary adenoma (author's transl)]. 737 Jan 37


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