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

A microcellular dispersion procedure for the rat neurohypophysis was developed, comprising tissue softening and dissociation using a special sieving sytringe. In preparatory studies the influence of mesh width, and treatment with trypsin, pronase or collagenase-hyaluronidase was investigated using light and electron microscopy, as well as with microchemistry by means of protein and lactate dehydrogenase activity determinations. Trypsinization gave the best results. In the final adopted procedure, 3 incubated neurohypophyses were sequentially sieved through a 200- and a 50-mum mesh. The resulting 50-mul dispersion was found to contain numerous ultrastructurally well-preserved pinched-off axonal endings (neurosecretosomes), and pituicytes often revealing processes. On the basis of DNA and oxytocin assays 11% of the pituicytes and 28% of the axonal cytoplasm were recovered. Oxytocin immunofluorescence microscopy showed hormone within the neurosecretosomes, but often also in the cytoplasm of pituicytes. Microdensity gradient centrifugation was performed on neurohypophyseal disperions, in order to obtain fractions enriched for neurosecretosomes and pituicytes. Fractions were characterized by means of phase contrast, oxytocin immunofluorescence and electron microscopy, as well as by oxytocin and DNA assays as respective markers. With a 10:14:22% (w/v) Ficoll gradient, fractions were obtained for which the relative purification was by a factor of 4 on the basis of DNA/oxytocin ratios.
 ...
PMID:Enzymic preparation of neurosecretosome- and pituicyte-enriched fractions from the rat neurohypophysis. 18 63

Vasopressin is shown to be a potent mitogen for Swiss 3T3 cells. The hormone (1--10 ng/ml) causes a striking shift of the dose--response curve for the effect of serum on thymidine incorporation by cultures of 3T3 cells arrested in the G1/G0 phase of the cell cycle. In the absence of added serum, the effect of vasopressin on DNA synthesis is greatly potentiated by insulin, epidermal growth factor, and a factor isolated from medium conditioned by simian virus 40-infected baby hamster kidney cells. The mitogenic effect of vasopressin is dependent on time and hormone concentration. In the presence of insulin, the half-maximal effect elicited by the peptide is obtained at 0.6 ng/ml. [Arg]Vasopressin and [Lys]vasopressin are equally potent. The vasopressins are 10(3)-fold more potent than oxytocin. In the presence of a low (2.5%) concentration of serum, vasopressins stimulate cell proliferation.
 ...
PMID:Vasopressin stimulation of mouse 3T3 cell growth. 31 1

Colchicine and other antitubulin agents markedly enhanced the stimulation of DNA synthesis by combinations of various growth factors such as epidermal growth factor, insulin, fibroblast-derived growth factor, and vasopressin in serum-free cultures of several quiescent 3T3 mouse fibroblast cell lines. Enhancing effects were observed based on continuous incorporation of [3H]thymidine into DNA as well as by autoradiographic labeling of cell nuclei. The concentration of colchicine and podophyllotoxin required to produce half-maximal enhancement of DNA synthesis stimulated by epidermal growth factor and insulin was 25-50 nM. Lumicolchicine did not produce enhancing effects. The disassembly of microtubules resulting from the action of colchicine, Colcemid, and vinblastine did not inhibit the stimulation of DNA synthesis in quiescent Swiss 3T3 fibroblasts by fetal bovine serum. We conclude that the cytoplasmic microtubule network in 3T3 mouse fibroblasts does not exert a positive regulatory function in the initiation of DNA synthesis but rather can produce a constraint on the initial action of the peptide growth factors in serum-free media.
 ...
PMID:Antitubulin agents enhance the stimulation of DNA synthesis by polypeptide growth factors in 3T3 mouse fibroblasts. 31 67

12-O-Tetradecanoyl-phorbol-13-acetate (TPA), in the absence of serum, acts synergistically with a range of polypeptide growth factors to stimulate DNA synthesis in quiescent Swiss 3T3 cells. These growth factors include epidermal growth factor (EGF), insulin, and the peptide produced by BHK cells transformed by SV-40 virus (fibroblast-derived growth factor, FDGF). Retinoids also show mitogenic synergism with TPA or polypeptide growth factors. The spectrum of mitogenic synergisms displayed by TPA are similar to those of vasopressin, a pituitary peptide. However, TPA and vasopressin do not synergistically interact to stimulate DNA synthesis in quiescent 3T3 cells. This suggests that TPA and vasopressin act via an identical biochemical pathway. Several lines of evidence suggest rapid postreceptor convergence of the mitogenic mechanisms of action of the hormone and the tumor promotor. Thus, vasopressin and TPA both inhibit EGF binding to cellular receptors. Furthermore, TPA and vasopressin induce a similar array of early events in quiescent cells--most strikingly, identical stimulation of Rb+ influx. Stimulation of ion flux is suggested as the possible convergence point of the pathway by which TPA and vasopressin act as mitogens.
 ...
PMID:Synergistic stimulation of early events and DNA synthesis by phorbol esters, polypeptide growth factors, and retinoids in cultured fibroblasts. 52 85

The acid phos phatase activity of the rat neurohypophysis was measured during increased gonadotrophic hormone levels, in diabetes insipidus (DI) (Brattleboro strain) and after water loading, i.e. conditions that interfere with the function of the hypothalamo-neurohypophyseal system (HNS). In addition determination of tissue protein, lipid and DNA and of water metabolism were performed. Neurohypophyseal acid phosphatase activity expressed on a dry weight basis increased under all conditions. For gonadectomized females, Brattleboro rats and water loaded males an increased water metabolism was observed. The increased acid phosphatase activity is interpreted as being related to disposal of release residues during stimulation of the HNS (increased gonadotrophic hormone levels and DI) and to disposal of neurosecretory material during inhibition (water loading).
 ...
PMID:Acid phosphatase activity in the rat neurohypophysis during increased levels of gonadothrophic hormones, in diabetes insipidus (Bratteboro strain) and after water loading. 94 60

This is a report of the second known case of a primary malignant granular-cell tumor of the cerebral hemispherical white matter. Two cell types may be distinguished apparently representing different developmental stages of otherwise identical tumor cells. Quantitative histochemical and biochemical studies have shown that tumor cells were containing markedly elevated levels of DNA and RNA. Only few ribosomes and polysomes could be detected, however, by electron microscopy. While cytophotometry disclosed only slightly elevated cytoplasmic proteins, there was a distinct increase in total protein concentration of tumor tissue per unit weight, as measured by conventional techniques. It is suggested that this increase is mainly attributable to structural proteins of cellular and subcellular elements of multiplicating malignant cells. A ratio of RNA to DNA in excess of 1 was found for white matter derived from the central tumor, while the ratios of control tissue were lowered to values far below one due to postmortem changes greatly reducing tissue concentrations of RNA. No detailed characterization of RNA was attempted. The nuclear DNA content of tumor cells reached values equivalent to chromosomal hexadekaploidy. This was in sharp contrast to control data from an Abrikossoff tumor of the oral cavity and from a neurohypophyseal tumorette ("choristoma"), respectively, displaying diploidy only associated with a much lesser increase of cytoplasmic RNA and proteins. Qualitative lipid studies were consistent with a marked active demyelination of the tumor centre as indicated by a severe reduction of cerebrosides and sulfatides and the presence of cholesterol esters. In addition there was a striking loss of phosphatidylethanolamine and a lesser one of sphingomyelin of white matter of both the tumor-stricken and the contralateral unaffected hemispherical regions, possibly suggesting a generally disturbed metabolism of myelin. It is not clear whether these general changes were resulting from the presence of the unilateral tumor or from precocious cerebral involution.
 ...
PMID:[Malignant granular-cell tumor of the cerebral white matter: morphological, cytophotometrical and neurochemical studies (author's transl)]. 116 67

Ribonucleoside-diphosphate reductase (ribonucleotide reductase, EC 1.17.4.1) is the enzyme responsible for the in vivo production of deoxyribonucleotides for DNA synthesis and is essential for cell proliferation. We examined the signal transduction pathways leading to expression of the M1 and M2 subunits of this enzyme in Swiss 3T3 mouse fibroblasts by Northern blot analysis. Stimulation of quiescent cells resulted in coordinate expression of both subunits, beginning at 8 hr after serum addition, in late G1 phase, and peaking at 18-24 hr. Serum increased M2 message to 30 to 50 times that of quiescent cells, in contrast with M1 message, which was increased 10 times. Agents that elevated cAMP, including forskolin, and the cAMP analogue 8-bromo-cAMP modestly stimulated gene expression. Each of these agents was synergistic with insulin, and these combinations induced expression equivalent to that induced by serum stimulation. Likewise, agents that activate protein kinase C such as phorbol 12,13-dibutyrate, bombesin, and vasopressin were also synergistic with insulin with respect to ribonucleotide reductase gene expression, as was epidermal growth factor, which stimulates receptor tyrosine kinase activity. The time course for induction of mRNA expression by each of these agents alone or in combination was identical to that for induction stimulated by serum. Finally, the synergistic effects apparent in Northern analysis of ribonucleotide reductase gene expression were mirrored in parallel determinations of DNA synthesis. Thus, the combinatorial nature of signal transduction pathways resulting in proliferation of Swiss 3T3 cells is expressed at the level of ribonucleotide reductase gene expression.
 ...
PMID:Synergistic and coordinate expression of the genes encoding ribonucleotide reductase subunits in Swiss 3T3 cells: effect of multiple signal-transduction pathways. 131 43

Hepatocyte growth factor (HGF) is the most potent known mitogen for hepatocytes in primary culture. However, the mechanisms through which HGF induces hepatocyte proliferation have not been defined. Here we have investigated the role of the adenylate cyclase, phosphoinositidase C and tyrosine kinase signalling systems in the control of hepatocyte proliferation by HGF using freshly isolated or cultured adult rat hepatocytes. We show that human recombinant HGF caused a dose-dependent increase in hepatocyte DNA synthesis with a maximal effect at 10 ng/mL and an EC50 of 5.9 ng/mL. HGF had no effect on hepatocyte adenylate cyclase activity or intracellular cAMP levels. Elevation of hepatocyte cAMP levels resulted in inhibition of HGF-stimulated DNA synthesis. HGF stimulated inositol phospholipid hydrolysis with a maximal effect at 25 ng/mL and potentiated the effect of vasopressin (10(-8) and 10(-9)M). HGF (100 ng/mL) caused an increase in the phosphorylation on tyrosine of an unknown hepatocyte protein with a molecular mass of 36 kDa. Thus, we have shown that HGF, like epidermal growth factor (EGF), can activate the phosphoinositidase C and tyrosine kinase systems in rat hepatocytes. As with EGF, these intracellular signalling systems may underlie HGF-induced hepatocyte proliferation.
 ...
PMID:Role of the adenylate cyclase, phosphoinositidase C and receptor tyrosyl kinase systems in the control of hepatocyte proliferation by hepatocyte growth factor. 132 55

Vasopressin is thought to play an important role, not only in the metabolism of water and electrolytes, but also in the regulation of renal hemodynamics. This year, great progress has been achieved in molecular biology of vasopressin receptors. First, the cloning of a complementary DNA, encoding the rat liver V1a arginine vasopressin receptor, was reported. The liver cDNA encodes a protein with seven putative transmembrane domains, which binds arginine vasopressin and related compounds with affinities similar to the native rat V1a receptor. The messenger RNA, corresponding to the cDNA, is distributed in rat tissues, known to contain V1a receptors. Second, the cloning of a complementary DNA encoding the rat kidney V2 arginine vasopressin receptor was also successful. The kidney cDNA encodes a protein with a transmembrane topography characteristic of G protein-coupled receptors. The receptor messenger RNA is detected only in the kidney. Last year, an orally active and specific vasopressin V1 receptor antagonist, OPC-21268 was first reported. The i.v. or p.o. administration of OPC-21268 dose-dependently inhibited vasopressin-induced vasoconstriction, while that induced by angiotensin II was not affected. OPC-21268 may have clinical potentials in certain hypertensive cardiovascular disorders. In addition, an orally active and specific vasopressin V2 receptor antagonist, OPC-31260 was also reported. Oral administration of OPC-31260 inhibited antidiuretic action of arginine vasopressin. OPC-31260 is thought to be useful in the treatment of certain disorders, such as the syndrome of inappropriate secretion of ADH (SIADH).
 ...
PMID:[Vasopressin (ADH)]. 133 14

Nephrogenic diabetes insipidus (NDI; designated 304800 in Mendelian Inheritance in Man) is an X-linked disorder with abnormal renal and extrarenal V2 vasopressin receptor responses. The mutant gene has been mapped to Xq28 by analysis of RFLPs, and tight linkage between DXS52 and NDI has been reported. In 1969, Bode and Crawford proposed, under the term "the Hopewell hypothesis," that most cases in North America could be traced to descendants of Ulster Scots who arrived in Nova Scotia in 1761 on the ship Hopewell. They also suggested a link between this family and a large Mormon pedigree. DNA samples obtained from 13 independent affected families, including 42 members of the Hopewell and Mormon pedigrees, were analyzed with probes in the Xq28 region. Genealogical reconstructions were performed. Linkage between NDI and DXS304 (probe U6:2.spl), DXS305 (St35-691), DXS52 (St14-1), DXS15 (DX13), and F8C (F814) showed no recombination in 12 families, with a maximum lod score of 13.5 for DXS52. A recombinant between NDI and DXS304, DXS305, was identified in one family. The haplotype segregating with the disease in the Hopewell pedigree was not shared by other North American families. PCR analysis of the St14 VNTR allowed the distinction of two alleles that were not distinguishable by Southern analysis. Carrier status was predicted in 24 of 26 at-risk females. The Hopewell hypothesis cannot explain the origin of NDI in many of the North American families, since they have no apparent relationship with the Hopewell early settlers, either by haplotype or by genealogical analysis. We confirm the locus homogeneity of the disease by linkage analysis in ethnically diverse families. PCR analysis of the DXS52 VNTR in NDI families is very useful for carrier testing and presymptomatic diagnosis, which can prevent the first manifestations of dehydration.
 ...
PMID:X-linked nephrogenic diabetes insipidus: from the ship Hopewell to RFLP studies. 135 65


1 2 3 4 5 6 7 8 9 10 Next >>