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)

A cytosolic protein is described which inhibits the binding of vasopressin and angiotensin to their rat liver receptors in the presence of calcium. The binding of insulin and transferrin was unaffected. Inhibition was temperature-dependent; it was maximal in 10 min at 37 degrees C, but required longer incubation times at lower temperatures. The pH optimum was 7.4. Inhibition also required the presence of calcium, with half-maximal inhibition at 6-8 microM calcium, but did not require any other low molecular weight cofactors. Inhibition could be reversed by washing the membranes at pH 5.5, but not by incubation with EGTA. Sephacryl S-300 chromatography showed that activity eluted in two peaks with approximate molecular weights of 70,000 and 150,000. In the presence of calcium, the inhibitory activity eluted at 150,000; in the absence of calcium, most of the inhibitory activity eluted at 70,000. A radiolabeled cytosolic protein with a molecular weight of 70,000 was eluted from inhibited rat liver membranes at pH 5.5 as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. We propose that vasopressin and angiotensin II, which both mobilize calcium in hepatocytes via phosphatidylinositol turnover, can, by this same mechanism, activate a protein(s) which reduces further binding to their receptors.
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PMID:Reversible inactivation of vasopressin and angiotensin II binding to hepatocyte membranes by a calcium-dependent, cytosolic protein. 300 31

Primary confluent monolayers were grown from proximal tubule fragments of rabbit kidneys. The fragments were obtained by gradient centrifugation and seeded on an ad hoc dish whose bottom was a permeable and transparent collagen membrane. The culture medium was a mixture of 50% Ham's F-12 and 50% Dulbecco's modified Eagle's medium supplemented with insulin, transferrin, ethanolamine, sodium selenite, and amino acids. The monolayers were studied at 6-14 days after seeding. Transmission electron microscopy revealed cuboidal cells 8.5-10.5 microns high, with a 1.5 to 2.5-microns apical brush border, abundant mitochondria, vacuoles, lysosomes, and irregular basal interdigitating processes. Cyclic AMP synthesis was stimulated by parathyroid hormone and was insensitive to vasopressin and isoproterenol. Electrophysiological studies performed with the same physiological salt solution on both sides revealed a transepithelial voltage of -2.6 +/- 0.6 mV (n = 10) and a basolateral membrane voltage of -51.0 +/- 4.5 mV (n = 13), both referred to the basal solution. The transepithelial electrical resistance was 7 +/- 2 omega X cm2. The apical membrane depolarized on addition of glucose to the apical side and hyperpolarized on removal of glucose. Changes in apical membrane voltage on addition of varying glucose concentrations (at [Na] = 135 mM, 37 degrees C) demonstrate the presence of a glucose transport system with an apparent Km of 3.54 +/- 0.54 and a Vmax of 7.2 +/- 0.4 mV. Thus this preparation exhibits morphological and electrophysiological characteristics of proximal tubule cells; these studies demonstrate the feasibility of the use of intracellular microelectrode techniques to study the transport properties of cultured epithelia.
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PMID:Electrophysiological studies on primary cultures of proximal tubule cells. 301 59

LLC-PK1L cells, a kidney-derived cell line, were able to grow in a chemically defined medium. Growth of the cells in the presence of retinol, ergocalciferol, d-alpha-tocopherol, 3,3',5-triiodothyronine, hydrocortisone, l-carnitine, d-l-methionine-S-methylsulfonium chloride, insulin, transferrin, cholesterol, and sodium linoleate increased the number of vasopressin receptors by 20- to 40-fold. All the newly detectable vasopressin receptors were coupled to the adenylate cyclase activity with similar efficiency. The same growth conditions did not alter the basal adenylate cyclase activity or the responses to calcitonin, parathyroid hormone, prostaglandin, adenosine, and GTP. In contrast, the increased responsiveness of the adenylate cyclase to vasopressin was associated with a reduced response to isoproterenol. Such an inverse correlation was also found when the time course of vasopressin receptor induction was studied. The supplemented medium permitted the growth of cells for several weeks. The effects of the enriched medium were fully reversible when we returned to the original cell growth medium. Thus such a cellular system appears as a useful tool for further work in cellular and kidney endocrinology and for detailing the molecular mechanisms of receptor-adenylate cyclase regulations.
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PMID:Regulation of hormonal responsiveness in LLC-PK1L cells grown in defined medium. 315 11

The kinetics of binding and endocytosis of 125I-human holotransferrin by isolated human brain capillaries was examined using this system as a model of the human blood-brain barrier (BBB). Both binding and endocytosis of the peptide by human brain capillaries was temperature-dependent and the binding was saturated by holotransferrin, but not by insulin, somatostatin, or vasopressin. Scatchard analysis of the binding reaction revealed a dissociation constant of 448 +/- 110 ng/mL (5.6 +/- 1.4 nmol/L) and a maximal binding constant (Ro) of 8.0 +/- 1.5 ng/mg protein. Thus, the affinity and capacity of the BBB transferrin receptor is within the same order of magnitude as the affinity and capacity of the BBB receptors for insulin, insulinlike growth factor-I, or insulinlike growth factor-II. The human brain capillary transferrin receptor was also detected with a mouse monoclonal antibody to the receptor using the avidin/biotin/peroxidase technique. In conclusion, these studies characterize the human BBB transferrin receptor and support the hypothesis that this receptor acts as a transport system which mediates the transcytosis of transferrin-bound iron through the brain capillary endothelial cell in man.
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PMID:Human blood-brain barrier transferrin receptor. 330 81

We report our experience in development of the in situ hybridization (ISH) procedure to detect messenger RNAs (mRNAs) coding for various molecules involved in endocrine glands and central nervous system activity, including mRNAs coding for endorphin precursors [preproenkephalin A (PPA), pro-opiocortin (POMC)], vasopressin, and transferrin. Various conditions of fixation and handling of the tissues were tested to establish optimal parameters for mRNA detection. Double-stranded DNA probes labeled by nick translation, synthetic oligonucleotides labeled at their 5' end, as well as single-stranded RNA probes were used, after incorporation of 32P- or 35S-labeled nucleotides. Specific requirements for efficient and reproducible ISH investigations are discussed. Cells expressing the PPA gene in the adrenal medulla and in the brain were detected by ISH. The results show that ISH is as sensitive as immunohistochemistry in detecting peptide-producing cells in the adrenal and that it allows detection of PPA cell bodies in brain in conditions in which they are inconstantly detected by immunohistochemistry. Unilateral destruction of substantia nigra provokes a dramatic decrease in the number of neurons expressing the PPA gene in the contralateral striatum. Cells expressing the POMC gene were detected in the pituitary of various species including man and in the rat arcuate nucleus. Neurons containing vasopressin mRNA were visualized in the supraoptic paraventricular and suprachiasmatic nucleus of the adult rat by using a synthetic oligonucleotide probe. Transferrin gene expression was shown in the central nervous system of the rat brain in two cell populations, the oligodendrocytes and the epithelial cells of the choroid plexus, by demonstration of simultaneous presence in them of transferrin immunoreactivity together with transferrin mRNA. These results show that the ISH procedure is a technique that can be routinely used to investigate gene transcription anatomically in complex heterocellular tissues such as the endocrine glands and the nervous system.
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PMID:In situ hybridization histochemistry for the analysis of gene expression in the endocrine and central nervous system tissues: a 3-year experience. 375 62

An epithelial cell line from pig kidney (LLC-PK1) with properties of proximal tubular cells can be maintained indefinitely in hormone-supplemented serum-free medium. Continuous growth requires the presence of seven factors: transferrin, insulin, selenium, hydrocortisone, triiodothyronine, vasopressin, and cholesterol. The hormone-defined medium (a) supports growth of LLC-PK1 cells at a rate of approaching that observed in serum-supplemented medium; (b) allows vectorial transepithelial salt and fluid transport as measured by hemicyst formation; and (c) influences cell morphology. The vasopressin dependency for growth and morphology can be partially replaced by isobutylmethylxanthine or dibutyryl cyclic AMP. The medium has been used to isolate rabbit proximal tubular kidney epithelial cells free of fibroblasts.
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PMID:Continuous growth of proximal tubular kidney epithelial cells in hormone-supplemented serum-free medium. 618 46

Injury or stress generates a vigorous metabolic response designed to establish the metabolic priorities required for the repair of injured tissues. In this condition, hormones commonly found to be elevated in the plasma include glucagon, catecholamines, glucocorticoids, growth hormone, aldosterone, and antidiuretic hormone. This hormonal profile results in rapid lysis of body protein, an increased rate of fat oxidation, and water and salt conservation. Rates of gluconeogenesis and ureagenesis are accelerated and may result in significant losses in lean body mass, a process that, if allowed to progress, will adversely affect patient survival. Exogenous nutrients provided to the critically ill patient may be poorly tolerated and may result in complications. Dextrose and intravenous fat emulsions provide the major sources of parenteral, nonprotein energy. These energy sources may not be metabolized efficiently in these patients, even though energy expenditure in this condition is increased significantly. Measurement of urinary nitrogen losses yields evidence useful in assessing the patient's degree of stress. In this manner, the patient's energy and protein requirements may be estimated. Formulations of amino acids, including the branched-chain amino acids, in higher concentrations have been reported to have anticatabolic effects and may improve the maintenance of lean body mass in stressed individuals. The stressed patient is prone to metabolic complications and, therefore, requires more careful monitoring of fluid, electrolyte, and acid-base balance, as well as renal, pulmonary, and liver function. Nutritional status is difficult to assess, since negative nitrogen balance may persist and the visceral proteins such as transferrin become altered in stress and, therefore, may not respond to nutritional intervention alone. The goal of nutritional therapy is the preservation of lean body mass by the safe and efficacious provision of metabolic substrate, thus improving patient survival.
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PMID:Nutritional support of the critically ill patient. 640 74

Endocrine abnormalities in patients with chronic renal failure are well documented. The present study aimed to assess the influence of long-term erythropoietin (EPO) therapy on endocrine abnormalities in hemodialyzed patients. Two groups of hemodialyzed patients, each of which comprised 17 subjects, were examined. The first group was treated by EPO (EPO group) while the second one did not receive this hormone (No-EPO group). A complete biochemical and hormonal check-up was performed before and at the 3, 6, 9, and 12 month points of the study period. Normal values for the estimated parameters were obtained in appropriately selected sex- and age-matched healthy subjects. After EPO therapy, an increase of the hematocrit value from 21.8 +/- 0.9 to 32.6 +/- 0.9% was observed, which was accompanied by a significant decline of plasma ferritin and saturation of transferrin. In patients of the No-EPO group, a significant although less marked rise of the hematocrit value (21.4 +/- 0.4 to 24.2 +/- 0.6%) was also noticed. EPO therapy did not change plasma levels of electrolytes (Na, K, Ca, inorganic phosphate), osteocalcin, creatinine, glucose, and alkaline phosphatase as well as plasma concentrations of calcium-related hormones (PTH, calcitonin, 1,25[OH]2D3), vasopressin, and triiodothyronine. EPO treatment induced a significant decrease in somatotropin, prolactin, follitropin, lutropin, ACTH, cortisol, plasma renin activity, aldosterone, noradrenaline, adrenaline, dopamine, glucagon, pancreatic polypeptide, and gastrin plasma levels and an increase in plasma insulin, estradiol, testosterone, atrial natriuretic peptide, thyrotropin, and thyroxine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Function of endocrine organs in hemodialyzed patients of long-term erythropoietin therapy. 762 22

In our studies of normal and neoplastic growth regulation, we have compared growth factor induced second messenger response and mitogenic activity in a rat hepatocarcinogenesis model. Inositol phosphate (IP) turnover was measured by incubating the cells with [3H]inositol and stimulating them with either epidermal growth factor, diferric transferrin, ferricyanide, vasopressin, norepinephrine, angiotensin II or bombesin for 2 min. The IPs formed were separated on HPLC. Mitogenic responses were monitored by bromodeoxyuridine uptake and labeling index. IP turnover was stimulated by vasopressin, norepinephrine and angiotensin II in both normal and nodular cells, but not by the other four agonists tested. The IP response was somewhat lower in cells from liver nodules. All compounds except bombesin were mitogenic to both nodular cells and cells from normal rats of different ages, with epidermal growth factor inducing the largest mitogenic response. Bombesin, on the other hand, had only a minor effect on normal cells, but induced a pronounced mitogenic response in nodular cells. In normal rats, the cells' ability to respond to growth stimulation decreased with increasing rat age. In this respect, nodular cells behaved in a way more like young normal cells than their age-matched controls. Taken together, these data support the view of liver nodules being a more autonomous cell population, with increased sensitivity to growth factors and possibilities for autocrine growth stimulation.
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PMID:Growth factor induced mitogenic effects and inositol phosphate responses in primary hepatocyte cultures from normal rat liver and rat liver nodules. 792 74

Colonies of small hepatocytes appeared after the culture of primary adult rat hepatocytes for 4 days in serum-free Dulbecco's modified Eagle's medium containing 10 mM nicotinamide and 10 ng/ml of epidermal growth factor (EGF), acidic and basic fibroblast growth factors (FGF), hepatocyte growth factor (HGF), or transforming growth factor-alpha (TGF-alpha). Every colony consisted of cells that each had a single nucleus and a higher nucleus/cytoplasm ratio than surrounding hepatocytes, and immunocytochemically the cells induced by any mitogen were stained with albumin, transferrin, cytokeratin-8 and -18. But these cells expressed neither cytokeratin-7 nor -19. When 6 x 10(5) cells were plated on 35-mm dishes, about 15 colonies per 1,000 attached cells were observed in the cultures treated with EGF, HGF, and TGF-alpha. Although FGFs could also induce colonies, their number was less than half of the number induced by EGF. Furthermore, the numbers of colonies induced by the combinations of EGF+HGF, EGF+TGF-alpha, and HGF+TGF-alpha were not different from those of the colonies induced by each mitogen alone. To examine the ability of co-mitogenic factors to induce small-cell colonies, angiotensin-II, insulin-like growth factor-I, norepinephrine, tumor necrosis factor, and vasopressin were used. In the cells cultured without EGF, these co-mitogens neither stimulated DNA synthesis nor induced colonies. On the other hand, in cells cultured with both EGF and each co-mitogen, although the DNA synthesis of the hepatocytes was enhanced, the number of colonies detected was not significantly different from the number which EGF alone could induce. These results showed that the small-cell colonies in primary cultures of rat hepatocytes were inducible by EGF, HGF, TGF-alpha, or FGFs and that the co-mitogens did not influence the formation of the small-cell colonies.
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PMID:Effects of mitogens and co-mitogens on the formation of small-cell colonies in primary cultures of rat hepatocytes. 825 57


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