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)

Dispersed corticotrophic cells of 3 patients with Nelson's syndrome were studied in tissue culture for up to 25 days. During this culture period a parallel decrease with time was seen in ACTH and beta-endorphin-like immunoreactivity ( LIR ) release. A concomitant decline was observed for intracellular hormones. The time course of hormone release showed a parallel secretion of ACTH and beta-endorphin- LIR up to 8 h. Both the release of ACTH and beta-endorphin LIR were stimulated by 0.1 microM lysine vasopressin (LVP) in all three adenoma cell cultures. Dexamethasone (0.1 and 1 microM) suppressed basal hormone secretion for 4 h. Synthetic ovine corticotrophin-releasing factor (CRF) at 10 and 100 nM stimulated the secretion of ACTH and beta-endorphin LIR maximally. This stimulation was higher than observed with maximal stimulative concentration of LVP (0.3 microM). The CRF-mediated hormone secretion was calcium-dependent. Dexamethasone (0.1 microM) blocked the stimulating effect of 10 nM CRF completely. Gel-filtration chromatography demonstrated the cells to secrete both beta-lipotrophin (beta-LPH) and beta-endorphin. The ratio of beta-LPH to beta-endorphin released remained constant upon stimulation by LVP and CRF. HPLC studies demonstrate the possibility that several beta-endorphin fragments, including alpha-endorphin and gamma-endorphin, were secreted by cells from a Nelson tumour. CRF caused a simultaneous parallel stimulation of the release of these peptides.
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PMID:ACTH and beta-endorphin secretion by three corticotrophic adenomas in culture. Effects of culture time, dexamethasone, vasopressin and synthetic corticotrophin releasing factor. 632 19

The intermittent reports concerning metabolic actions of neurohypophysial extracts or hormones encouraged us to study the effect of these substances on the function of the endocrine pancreas. A surprisingly small amount of neural lobe (NL) extract (0.025 NL eq/ml) stimulated a 425% increase in the release of glucagon from islets isolated from the pancreas of the rat. Gel filtration of the extract produced an elution profile of glucagon-releasing activity that was superimposable on the profiles of oxytocin (OT) and arginine vasopressin (AVP). Synthetic OT and AVP each elicited a concentration-dependent stimulation of glucagon release but failed to influence insulin release in medium 199 containing 5.6 mM glucose. They were effective at 0.2 ng/ml (+55%, +50%) and produced a striking increase (five- to sevenfold) at 20 ng/ml. The response to each peptide was greatly diminished in the presence of a higher concentration of glucose (11 mM). The lysine, desamino-, and 1,6-aminosuberyl analogues of vasopressin, vasotocin, and AVP are equipotent peptides, whereas the desglycinamide analogue, pressinoic acid, and angiotensin II were inactive. Injection of AVP (1 microgram iv) produced a rapid increase in peripheral glucagon (+185% in 5 min). The response to injection of OT was less rapid (+105% in 15 min), but in each case elevation of insulin was also observed. Our results provide evidence that OT and AVP can act directly on the endocrine pancreas and may help explain previous reports of metabolic actions of these peptides.
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PMID:Actions of neurohypophysial peptides on pancreatic hormone release. 636 29

[he concentrations of immunoreactive (ir-) peptides derived from the opioid peptide precursors proenkephalin A (Met-enkephalin), proenkephalin B [dynorphin (DYN)-(1-17), dynorphin-(1-8), dynorphin B, alpha-neoendorphin (alpha-NEO-E), beta-NEO-E] and proopiomelanocortin [beta-endorphin (beta-END)], and of the neurosecretory hormones vasopressin and oxytocin increased between approximately 10-fold and 50-fold from birth to adulthood in the rate hypothalamus. Gel filtration and HPLC analysis of proenkephalin B-derived opioid peptides revealed that in 3-day-old rats the predominant portion of ir-dynorphin-(1-17) and a substantial part of ir-dynorphin B consisted of a high (6000) mol wt species, a common precursor peptide for DYN-(1-17) and DYN B. In adults rats, however, authentic DYN-(1-17) and DYN B were found to be the major ir-forms. The mol wt patterns of ir-DYN-(1-8), ir-alpha-NEO-E and ir-beta-NEO-E did not differ between 3-day-old and adult rats and reflected predominantly the respective authentic opioid peptides. Taking into consideration the developmental changes in the mol wt pattern of ir-DYN-(1-17), authentic DYN-(1-17) was 5 times lower in concentration than DYN-(1-8) in 3-day-old rats, whereas in adults these opioid peptides occurred in equimolar concentrations. These findings suggest that the posttranslational processing of the precursor proenkephalin B changes in the course of postnatal development. Ir-beta-END in the hypothalamus of newborn and adult rats consisted exclusively of beta-END-sized peptides which were not (unlike those in the intermediate pituitary lobe) alpha-N-acetylated. Thus, in the hypothalamus, the enzymatic processing of the opioid peptide precursor proopiomelanocortin to beta-END seems to be fully active at birth, in contrast to that of proenkephalin B.
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PMID:Evidence for a differential postnatal development of proenkephalin B (= prodynorphin)-derived opioid peptides in the rat hypothalamus. 654 67

In addition to oxytocin (OT), vasopressin (AVP) and their respective neurophysins (NPs), another [35S]cysteine incorporating component is present in the guinea pig neurohypophysis. Gel filtration and Con A affinity chromatography revealed that this component was larger than NP and was glycosylated. NP-immunoreactivity was assessed using antisera which distinguish the OT- and AVP-related NPs. Whilst the anti-NP antiserum detected only one component (guinea pig NP), the anti-NP antiserum detected both NP and the glycosylated 35S-labelled component. These results suggest that a significant amount of NP in guinea pig neural lobes bears a glycopeptide extension and represents a partially processed form of the AVP precursor in this species.
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PMID:Characterisation of an intermediate in neurophysin biosynthesis in the guinea pig. 664 47

Filtered proteins including insulin are absorbed in the proximal tubule by means of pinocytosis. The first step in this process is binding of the protein to brush border membrane. As it is not known whether absorption exhibits specificity, we set out to determine whether specific binding sites for insulin are present in brush border membranes. Rabbit-isolated brush border membranes were incubated with 125I-insulin and varying concentrations of cold insulin or other peptide hormones. Binding and degradation of 125I-insulin occurred in a time- and temperature-dependent manner. Native insulin competitively inhibited 125I-insulin binding, but calcitonin, arginine vasopressin, glucagon, and growth hormone (10(-6) M) were relatively ineffective. Nonspecific binding averaged one-third of the total radioactivity bound. Scatchard analysis of binding data revealed two classes of insulin receptors: high affinity, low capacity receptors and low affinity, high capacity receptors. Gel filtration analysis of 125I-insulin exposed to brush border membrane revealed the formation of low-molecular-weight products similar to that produced by intact kidneys. The degrading process exhibited some specificity, for cold insulin (10(-6) M) was more effective than calcitonin, vasopressin, glucagon, or growth hormone in inhibiting degradation (32% versus less than 13% inhibition; P less than 0.01). Whether this reflects inhibition of insulin specific binding before exposure to degradation or inhibition of specific enzymes is unclear. In summary, it appears that renal brush border membranes have a major insulin-specific receptor component that could potentially mediate tubular insulin absorption. In addition, there is a smaller nonspecific component that may also have the potential to mediate insulin absorption. Finally, it appears that brush border membranes have the ability to degrade insulin to low-molecular-weight products by a process that exhibits some specificity for insulin.
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PMID:Binding and degradation of insulin by isolated renal brush border membranes. 676 Dec

The native plasma of patients suffering from renal insufficiency inhibited the parathyroid hormone (PTH), the vasopressin (VP) and the NaF-activated adenylate cyclase (AC) in bovine renal plasma membranes. A crude immunoglobulin fraction, prepared by (NH4)2SO4 precipitation, decreased only the hormone, but not the NaF activated AC. Chromatography of the native plasma on a AcA 34 column revealed two peaks inhibiting the PTH and to a lesser extent the VP dependent AC. Only the second peak reduced the NaF stimulated cAMP production. None of the column samples inhibited the isoproterenol stimulated adenylate cyclase in turkey red blood cells. Further purification of the first peak on a Sepharose 6B column confirmed previous results that immunoglobulins may block the PTH receptor in the kidney. Repurification of the second peak of inhibition on a Bio-Gel P10 column suggested that small peptides crossreacting in the radioimmunoassay for PTH may desensitize the hormonal receptor.
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PMID:Inhibition of renal adenylate cyclase by plasma from uremic patients. 715 74

We have previously measured the individual content of immunoreactive vasopressin (AVP), oxytocin (OT) and vasotocin (AVT) in 155 human pineal glands, and report here identification and measurement of the neurophysin (Np) content of the same glands, using specific homologous human neurophysin I (HNp I) and neurophysin II (HNp II) radioimmunoassays. Median values for HNp I were for men 47 ng/gland (range, 5 to 1360) and for women 24 ng/gland (range, 5 to 1000); median values for HNp II were respectively 7 ng/gland (range, 2 to 191) and 15 ng/gland (range, 2 to 356) with no significant difference between men and women for HNp I and HNp II but a significant difference (p less than 0.001) between HNp I and HNp II for both sexes. Gel filtration showed that pineal neurophysins were eluted at the same volume as both standard Np and Np from human posthypophyses used as controls. HNp I correlated both with AVP (rs = 0.54 for men and 0.55 for women) and OT (rs = 0.86 for men and 0.57 for women) but not with AVT, while HNp II correlated with AVP (rs = 0.52 for men and 0.53 for women) and OT (rs = 0.92 for men and 0.50 for women) but not with AVT. This study thus confirms the presence of two neurophysins in the human pineal gland and further indicates that they are related to AVP and OT concentrations in the same gland. The results also imply, however, that the presence of immunoreactive AVT (more probably a closely related peptide) is independent of the neurophysins.
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PMID:Presence of neurophysins I and II in the human pineal gland: comparison with the content of neurohypophyseal hormones. 717 24

Previously it has been shown that vasopressin (VP) and oxytocin are converted by aminopeptidase activity in brain membranes into fragments with potent CNS activities. This report concerns the properties of this enzyme activity, addressed as VP-converting aminopeptidase (VP-AP) activity, in membranes of the rat brain. The VP-AP activity had a pH optimum at pH 7.0 and had a Km of 17 microM for its action on VP. Amastatin was the most potent aminopeptidase inhibitor. Enzyme activity was inhibited by relatively low concentrations of metal chelators. Treatment of brain membranes by EDTA resulted in loss of enzyme activity that was completely reversed by 10 microM Zn2+, indicating that VP-AP activity is a metallopeptidase. Several VP analogues and fragments, in particular VP(1-8), inhibited the action of enzyme activity on VP. Among peptides unrelated to VP, angiotension I, somatostatin, and porcine ACTH(1-39) markedly inhibited enzyme activity. Solubilization of VP-AP activity from brain membranes and gel filtration on Sephadex G200 showed two peaks of activity, one eluting with an apparent mass of about 140 kDa, the other in the void volume. Gel filtration fractions were able to convert [3H][Phe3]VP in a step-wise fashion. The VP-AP-like activity was found in many tissues outside the brain. Highest activity was present in lung, kidney, parts of the gastrointestinal tract, ovary, and uterus. The results indicate that VP-AP activity is a widely distributed enzyme with probably multiple functions, one of which involves the metabolism of vasopressin in the brain.
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PMID:Properties of aminopeptidase activity involved in the conversion of vasopressin by rat brain membranes. 799 91

Although many proteins and peptides were produced by gene-technology, their administration routes are limited to be i.v. route. To increase the clinical use of these products, oral dosage form is required. However, in the case of oral administration, proteins are degraded by digestive fluid having strong protease activity. To decrease the protease activity, protease inhibitors are administered concomitantly with proteins. Aprotinin, soybean trypsin inhibitors and gel-forming polymer such as Polycarbophil are representative protease inhibitors. Gel-forming polymers have both protease inhibiting activity and absorption enhancing effect on protein/peptides. The usefulness of these protease inhibitors have been suggested as an additive for the oral delivery of G-CSF and vasopressin derivatives.
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PMID:[Improvement of drug bioavailability using protease inhibitors]. 954 42

Arginine vasopressin (AVP) is a major antidiuretic hormone, the overproduction of which causes diluting hyponatremia in humans and is called the syndrome of inappropriate antidiuresis (SIAD). To study physiological changes resulting from AVP overproduction and to develop an animal model of hyponatremia, the human AVP gene was expressed under the control of the metallothionein promoter in transgenic (Tg) rats. Analyses of AVP immunoreactivity (irAVP) in the tissues revealed that the transgene is expressed mainly in the central nervous system. Gel filtration showed that irAVP in the brain and plasma was properly processed AVP. AVP purified from the brains of both Tg and control rats also exerted equal bioactivity to generate cAMP in LLC-PK1 cells. The founder rats did not show any physical or anatomical abnormalities. Under basal conditions, Tg rats had high plasma AVP levels (Tg 13.8 +/- 2.5 pg/ml; control 2.7 +/- 1.2 pg/ml; n=6 in both groups; means +/- S.E.M.), decreased urine volume, and normal plasma [Na(+)]. Hypertonic saline injected i.p. did not affect AVP secretion in Tg rats. In response to a zinc-supplemented liquid diet, plasma AVP decreased in control rats, but increased in Tg rats (Tg 32.7 +/- 2.7 pg/ml; control 1.0+/-0.1 pg/ml; n=6), resulting in hyponatremia (Tg 135.2 +/- 2.5 mEq/l; control 140.8 +/- 0.4 mEq/l; n=6). To our knowledge, this is the first transgenic animal to show diluting hyponatremia. This transgenic rat may therefore provide a useful model in which to investigate various physiological alterations resulting from the oversecretion of AVP which involve SIAD, stress response, behavior, and blood pressure.
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PMID:Overexpression of vasopressin in the rat transgenic for the metallothionein-vasopressin fusion gene. 1192 82


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