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)

The Brattleboro strain of Long-Evans hooded rats has hereditary hypothalamic diabetes insipidus due to the inability to produce antidiuretic hormone. Animals homozygous for this autosomal recessive trait have extreme polyuria and polydipsia, whereas heterozygotes are less severely affected. Light and electron microscopy were used to study the interstitial tissue of the renal papilla of Brattleboro rats and normal Long-Evans rats. Staining with alcian blue or colloidal iron revealed that homozygous Brattleboro rats (DI) have greatly reduced quantities of glycosaminoglycans in the papillary interstitium. Heterozygotes showed staining similar but not identical to that of normal rats. The papillary interstitial cells of DI rats lacked the cytoplasmic processes seen in normal rats, and the normal relationship of these cells to the tubular elements of the papilla was absent. Electron microscopy revealed that the papillary interstitial cells of DI rats appeared less active than those of heterozygous or normal rats. In DI rats these cells displayed reduced numbers of lipid droplets and mitochondria, and the Golgi apparatus and rough endoplasmic reticulum were poorly developed. The altered ultrastructure of the papillary interstitial cells may be responsible for the reduction of interstitial glycosaminoglycans in DI rats. Glycosaminoglycans possess properties which may contribute to urinary concentration, It is suggested that the interstitial tissue of the renal papilla is influenced by antidiuretic hormone.
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PMID:Histochemistry and ultrastructure of the interstitium of the renal papilla in rats with hereditary diabetes insipidus (Brattleboro strain). 740 59

Congenital nephrogenic diabetes insipidus is a recessive hereditary disorder characterized by the inability of the kidney to concentrate urine in response to vasopressin. Recently, we reported mutations in the gene encoding the water channel of the collecting duct, aquaporin-2 (AQP-2) causing an autosomal recessive form of nephrogenic diabetes insipidus (NDI). Expression of these mutant AQP-2 proteins (Gly64Arg, Arg187Cys, Ser216Pro) in Xenopus oocytes revealed nonfunctional water channels. Here we report further studies into the inability of these missense AQP-2 proteins to facilitate water transport in Xenopus oocytes. cRNAs encoding the missense AQPs were translated with equal efficiency as cRNAs encoding wild-type AQP-2 and were equally stable. Arg187Cys AQP2 was more stable and Gly6-4Arg and Ser216Pro AQP2 were less stable when compared to wild-type AQP2 protein. On immunoblots, oocytes expressing missense AQP-2 showed, besides the wild-type 29 kDa band, an endoplasmic reticulum-retarded form of AQP-2 of approximately 32 kD. Immunoblots and immunocytochemistry demonstrated only intense labeling of the plasma membranes of oocytes expressing wild-type AQP-2. Therefore, we conclude that in Xenopus oocytes the inability of Gly64-Arg, Arg187Cys or Ser216Pro substituted AQP-2 proteins to facilitate water transport is caused by an impaired routing to the plasma membrane.
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PMID:Water channels encoded by mutant aquaporin-2 genes in nephrogenic diabetes insipidus are impaired in their cellular routing. 753 61

The distribution of vasopressin (VP)-immunoreactive neuronal perikarya and its fibers had been studied in the hypothalamus of Tupaia belangeri using the avidin-biotin complex (ABC) immunocytochemical technique. VP-immunoreactive neurons were found in the hypothalamic paraventricular nucleus (PVN), supraoptic nucleus (SON), accessory supraoptic nucleus (ASN), hypothalamic lateral nucleus (HLN), perifornical nucleus (PFN) and ansa peduncularis (AP) but not in the suprachiasmatic nucleus (SCN). VP neurons of the rostral PVN could be divided into three subnuclei and the caudal PVN could also be divided although not so distinctly into four subnuclei. The VP-immunoreactive neuronal perikarya of SON were divided into three parts, i.e., medioventral, mediodorsal and laterodorsal. Three types of VP neuronal perikarya, i.e., large, medium and small cells, existed in PVN and SON. Between PVN and SON, there were a large number of VP immunopositive nerve fibers. In addition, there were numerous immunopositive fibers projecting into the infundibulum and the neurohypophysis. VP-immunoreactive-positive products localized in the large granular vesicles and on the rough-surfaced endoplasmic reticulum could be seen under electron microscope.
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PMID:Studies on the distribution of vasopressin-immunoreactive neuronal perikarya and their fibers in the hypothalamus of Tupaia belangeri. 758 4

The role of a trimeric GTP-binding protein (G-protein) in the mechanism of vasopressin-dependent Ca2+ inflow in hepatocytes was investigated using both antibodies against the carboxyl termini of trimeric G-protein alpha subunits, and carboxyl-terminal alpha-subunit synthetic peptides. An anti-Gi1-2 alpha antibody and a Gi2 alpha peptide (Gi2 alpha) Ile345-Phe355), but not a Gi3 alpha peptide (Gi3 alpha Ile344-Phe354), inhibited vasopressin- and thapsigargin-stimulated Ca2+ inflow, had no effect on vasopressin-stimulated release of Ca2+ from intracellular stores, and caused partial inhibition of thapsigargin-stimulated release of Ca2+. An anti-Gq alpha antibody also inhibited vasopressin-stimulated Ca2+ inflow and partially inhibited vasopressin-induced release of Ca2+ from intracellular stores. Immunofluorescence measurements showed that Gi2 alpha is distributed throughout much of the interior of the hepatocyte as well as at the periphery of the cell. By contrast, Gq/11 alpha was found principally at the cell periphery. It is concluded that the trimeric G-protein, Gi2, is required for store-activated Ca2+ inflow in hepatocytes and acts between the release of Ca2+ from the endoplasmic reticulum (presumably adjacent to the plasma membrane) and the receptor-activated Ca2+ channel protein(s) in the plasma membrane.
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PMID:Evidence that the pertussis toxin-sensitive trimeric GTP-binding protein Gi2 is required for agonist- and store-activated Ca2+ inflow in hepatocytes. 759 76

Hormones that elevate cytosolic Ca2+ concentrations ([Ca2+]cyt) often use Ca2+ as a messenger to activate intramitochondrial metabolic processes. However, the mitochondrial Ca2+ level also regulates the activation of the mitochondrial permeability transition (MPT), a process that involves the assembly of a high conductance proteinaceous pore across the inner and outer membrane. Studies on intact liver cells indicate that the MPT is a critical step in the cell killing induced by anoxia or respiratory inhibitors. In this study, we used freshly isolated hepatocytes to investigate to what extent the elevation of [Ca2+]cyt by vasopressin or other agonists causes Ca2+ accumulation in the mitochondria and how this treatment affects the mitochondrial susceptibility to undergo the MPT. Hepatocytes were incubated with vasopressin, glucagon, or with thapsigargin (an inhibitor of the endoplasmic reticulum Ca2+ pump) prior to permeabilization with digitonin. Mitochondrial Ca2+ accumulation was determined by following the ionomycin-induced Ca2+ release in permeabilized cells and mitochondrial swelling was studied by following cyclosporin A-sensitive light scattering changes induced by phenyl-arsenoxide and rotenone. The results indicate that agents that elevate [Ca2+]cyt cause a significant Ca2+ accumulation in the mitochondria. Excessive Ca2+ accumulation (> 10-fold increase over basal levels) was obtained with the combination of vasopressin and glucagon or with incubations containing thapsigargin. These conditions were also associated with a marked increase in rotenone-induced mitochondrial swelling. However, the more modest increase in mitochondrial Ca2+ content after treating cells with vasopressin alone did not enhance the swelling response; instead, vasopressin suppressed mitochondrial swelling compared to control incubations. Vasopressin also partly suppressed the swelling associated with thapsigargin treatment, although it did not significantly affect the Ca2+ accumulation under these conditions. This effect of vasopressin was mimicked by phorbol ester, suggesting a role for protein kinase C. The data indicate that mitochondrial Ca2+ accumulation following elevation of elevation of [Ca2+]cyt enhances the susceptibility for activation of the MPT, a response that may increase cell injury during anoxia or in response to other challenges. However, hormones also activate protective responses in the cell that suppress the MPT.
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PMID:Calcium ion-dependent signalling and mitochondrial dysfunction: mitochondrial calcium uptake during hormonal stimulation in intact liver cells and its implication for the mitochondrial permeability transition. 759 32

The endoplasmic reticulum is generally absent from schematic representations of transport phenomena, although it shows a well-organized network in most transport epithelial cells. In order to examine the correlation between this organelle and cellular activity, bladders of Bufo marinus were studied under different experimental conditions and fixed by immersion in glutaraldehyde, followed by OsO4 impregnation for 3 days. Normal granular and mitochondria-rich cells showed a rich cytoplasmic network of canaliculi, well-impregnated by osmium deposits. Following a 2 to 15-min stimulation (serosal bath) with arginine vasopressin, the V2 receptor agonist dD-arginine-vasopressin or cyclic AMP (cAMP), the staining of endoplasmic reticulum in granular cells disappeared. After washing out of the hormone or the agonist, impregnation of the endoplasmic reticulum could be observed once again. Arginine vasopressin did not modify the impregnation of endoplasmic reticulum of either mitochondria-rich or basal cells. Our data indicate a correlation between the reactivity of endoplasmic reticulum to osmium, and a cAMP-dependent effect of arginine vasopressin through its V2 receptors. Incubation of arginine vasopressin through its V2 receptors. Incubation of toad bladders carried out with agents interfering with cellular calcium (calcium ionophores, high or low bath calcium) or with calcium release from the endoplasmic reticulum (TMB-8, thapsigargin) suggested that an early step in the cAMP-dependent effect of arginine vasopressin must involve the release of intracellular calcium from the endoplasmic reticulum. However, calcium ATPases in this organelle do not seem to participate in the hormonal effect.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reversible histochemical modifications of endoplasmic reticulum following arginine vasopressin stimulation of granular cells of toad bladder. 778 Oct 34

Preembedding immunoperoxidase staining methods were used to characterize tyrosine hydroxylase-immunoreactive (TH-ir) elements in the caudal ventrolateral medulla, and to determine the extent to which neurons of the A1 cell group are directly innervated by projections of the nucleus of the solitary tract (NTS). TH-ir neurons in the A1 region were medium-sized and multipolar. They possessed rounded nuclei with infrequent invaginations, well-developed Golgi apparati, high cytoplasmic densities of mitochondria, and a low to moderate tendency for rough endoplasmic reticulum (RER) to align in parallel stacks. A1 cell bodies were commonly juxtaposed to TH-positive and TH-negative neurons, myelinated profiles, glia and/or vascular elements, but close membrane appositions were only seen with glial elements. Synaptic input to A1 neurons was predominantly asymmetric, provided virtually exclusively by non-TH-ir terminals, and directed principally to dendritic shafts; A1 somata are relatively sparsely innervated. In a second experiment, silver-intensified immunogold localization of TH-ir was combined with immunoperoxidase labeling for anterogradely transported Phaseolus vulgaris-leucoagglutinin (PHA-L), following tracer injections in the caudal aspect of the medial division of the NTS. These experiments revealed a small proportion of PHA-L-labeled axon terminals that made asymmetric contacts with dendritic shafts of TH-ir neurons. These results suggest that the fine structure and synaptic input of A1 neurons are somewhat distinct from that of rostrally situated C1 catecholamine cells. In addition, while they document a direct NTS-A1 projection that may participate in the interoceptive control of vasopressin secretion, the bulk of ventrolaterally directed projections from the caudomedial NTS contact noncatecholaminergic elements in the A1 region, some of which may correspond to so-called depressor neurons implicated in the baroreflex control of sympathetic outflow and vasopressin secretion.
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PMID:A1 catecholamine cell group: fine structure and synaptic input from the nucleus of the solitary tract. 789 40

Molecular biological and immunocytochemical data demonstrate nonhomologous crossing-over between the closely linked vasopressin (VP) and oxytocin (OT) genes in rat hypothalamic neuroendocrine neurons. Reverse transcription of hypothalamic total RNA from wild-type or homozygous Brattleboro aged rats combined with polymerase chain reaction (PCR) amplifications in the presence of appropriate 5' forward and 3' reverse primers deduced from the VP and OT cDNA sequences yielded PCR products that, upon cloning and sequencing, revealed several hybrid transcripts. They encode the N-terminal part of the VP precursor fused to the C-terminal part of the OT precursor (VP/OT transcripts) and vice versa (OT/VP transcripts). VP/OT hybrid precursor proteins have been identified immunocytochemically in enlarged cisternae of the rough endoplasmic reticulum, yet there is no evidence that the products can be secreted from affected cells. Recombination appears to be a rather frequent genetic event affecting about 0.06-0.1% of the rat vasopressinergic magnocellular neurons in aged rats.
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PMID:Somatic nonhomologous crossing-over between neuropeptide genes in rat hypothalamic neurons. 797 73

We found that thapsigargin (Tg), a non-phorbol ester type tumor promoter that specifically inhibits endoplasmic reticulum Ca(2+)-ATPase, transiently increased the level of cytosolic free calcium ([Ca2+]i) and subsequently induced chromatin condensation, nuclear fragmentation, and internucleosomal DNA cleavage in cultured PLC/PRF/5 human hepatoma cells. These alterations were followed by the loss of plasma membrane integrity and by cell death. Epidermal growth factor (EGF) and vasopressin similarly elevated [Ca2+]i without causing DNA fragmentation which is characteristic of apoptosis. Consequently, the elevation of [Ca2+]i itself was not sufficient for causing Tg-induced cell death. On the other hand, preculturing the cells with Tg completely suppressed Ca2+ mobilization induced by EGF and vasopressin; a result that strongly suggests that Tg depleted the endoplasmic reticulum Ca2+ pool. Such depletion is hypothesized to induce apoptotic cell death in this hepatoma cell line by changing the nuclear Ca2+ levels which probably produce a structural change in chromatin.
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PMID:Thapsigargin-induced persistent intracellular calcium pool depletion and apoptosis in human hepatoma cells. 801 72

A key protein component of the amiloride-sensitive sodium channel has been cloned from rat colon and human lung. It may represent the first member of a new family of ionic channels expressed from nematode to human. The biochemical properties of the rat protein, a 699 amino acids long polypeptide, have been analyzed. Four polyclonal antibodies raised against distinct parts of the channel immunoprecipitated a glycosylated protein of 96 kDa after cRNA expression in oocytes as well as after in vitro translation. When expressed alone into oocytes, the protein was not stable; most of it remains stacked into the endoplasmic reticulum. This results in a very low yield of complete maturation of the protein at the cell surface after expression from the pure cRNA. To determine the membrane topology of the protein, in vitro translation by a rabbit reticulocyte lysate was performed followed by insertion into canine pancreatic microsomes and protease digestion. Analysis revealed a model with only two transmembrane alpha helices and a large extracellular domain of about 500 amino acids. The NH2 and COOH termini are cytoplasmic. Protease digestion results suggest the possible presence of a structural element that could have a function similar to that of the H5 segment in K+ channels. The model indicates that there is no cytoplasmic site for protein kinase A phosphorylation. The well known regulation of the channel activity by hormones that activate this kinase such as vasopressin might thus be situated on another channel component.
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PMID:Biochemical analysis of the membrane topology of the amiloride-sensitive Na+ channel. 817 16


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