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)

One of the major biological targets of free radical oxidations, prone, for anatomical reasons, to oxidative challenges, is the cardiovascular system. In the present paper the effect of hydrogen peroxide on intracellular ionized calcium ([Ca2+]i) homeostasis in smooth muscle cells (SMC) is studied, the major aim of the study being a better understanding of the protective effect of antioxidants and Ca2+ channel blockers. The exposure of SMC to 300 microM H2O2 induced a rapid increase of [Ca2+]i, followed by a decrease to a new constant level, higher than the basal before the oxidative challenge. When incubation medium was Ca2+ free, the pattern of [Ca2+]i change was different. The rapid increase was still observed, but it was followed by a rapid decrease to a level only slightly above the basal before the oxidative challenge. The involvement of intracellular Ca2+ stores was tested by using vasopressin, a hormone able to induce discharge of inositol 1,4,5-triphosphate-sensitive Ca2+ stores. When H2O2 was added after vasopressin no [Ca2+]i increase was observed. Treatment of cells, in which the stable increase of [Ca2+]i was induced by H2O2, with disulfide reducing compounds, induced a progressive decrease of [Ca2+]i toward the level observed before the oxidative challenge. Calcium channel blockers and antioxidants, on the other hand, effectively prevented the stabilization of [Ca2+]i at the high steady-state, after the internal Ca2+ release phase. Dihydropyridine Ca2+ channel blockers were by far more active than verapamil and among those the most active was lacidipine. Also the antioxidants trolox and N,N'-diphenyl-1,4-phenylenediamine both prevented the [Ca2+]i unbalance. These results suggest that Ca+ channel blockers and antioxidants, although inactive on oxidative stress-induced Ca2+ release from intracellular stores, prevent the increased influx apparently related to a membrane thiol oxidation.
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PMID:Effect of hydrogen peroxide on calcium homeostasis in smooth muscle cells. 149 46

It has been suggested that the von Willebrand factor antigen (vWF:Ag) may be a clinical marker for pulmonary endothelial cell injury. An ELISA was developed for the measurement of rat vWF:Ag. Rat lungs were isolated and perfused with a recirculating, blood-free, physiologic salt solution. Circulating levels of vWF:Ag and the eicosanoids thromboxane B2 (TXB2) and prostaglandin 6-keto F1-alpha (6-keto PGF1 alpha) were measured before and after different forms of insult. The addition of phospholipase C (PLC) or hydrogen peroxide (H2O2) to the perfusate caused lung damage as manifested by pulmonary artery pressure increase and pulmonary edema. This was paralleled by significant release of vWF:Ag, TXB2, and 6-keto PGF1 alpha. Increased hydrostatic pressure caused pulmonary edema without vWF:Ag and eicosanoid release. The addition of vasopressin to the perfusate caused vWF:Ag release but no lung injury and no release of eicosanoids. It is concluded that in the rat model, vWF:Ag release is a nonspecific marker for lung injury.
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PMID:Release of von Willebrand factor antigen (vWF:Ag) and eicosanoids during acute injury to the isolated rat lung. 159 10

The effects of calmodulin antagonists on the capacity of hydrogen-translocating shuttles were studied in the perfused rat liver. The capacity was estimated by measuring the changes in the rate of production of glucose from sorbitol during the oxidation of ethanol [T. Sugano, T. Ohta, A. Tarui, and Y. Miyamae. Am. J. Physiol. 251 (Endocrinol. Metab. 14): E385-E392, 1986]. Thyroxine given to intact rats increased the activity of alpha-glycerophosphate dehydrogenase (alpha-GPD). Glucocorticoid replacement in adrenalectomized rats decreased the activity of the alpha-GPD to values obtained after treatment with PTU. In either thyroxine-treated or steroid-replaced rats, the capacity of hydrogen-translocating shuttles increased markedly. However, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), trifluoperazine, and chlorpromazine inhibited the increased capacity in steroid-replaced rats and had no effect on the increased capacity in thyroxine-treated rats. W-7 inhibited the stimulatory effects of norepinephrine on the capacity of the malate-aspartate shuttle without inhibition of efflux of intracellular Ca2+. The stimulatory effects of vasopressin on the malate-aspartate shuttle were also inhibited by W-7, trifluoperazine, and chlorpromazine. The results suggest that the malate-aspartate shuttle may be regulated by Ca(2+)-calmodulin.
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PMID:Effects of calmodulin antagonists on hydrogen-translocating shuttles in perfused rat liver. 188 79

In experiments with isolated animal hearts it has been ascertained that free hemoglobin, lactic acids, catecholamines, vasopressin and acetylcholine at the concentrations they appear in patients' blood during open heart surgeries can produce cardiodepressive effects and cause acute heart failure. Cardiac reperfusion with a solution containing 20% less sodium, potassium, calcium, magnesium and hydrogen ions leads to severe heart failure: lower osmotic capacity and/or concurrent smaller Na+ and H+ concentrations were responsible for myocardial contractility disturbances.
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PMID:[Causes of disorders of the contractile function of the heart after cardioplegia]. 204 40

Optical methods have recently become available for continuously imaging the free concentrations of important ions and second messengers such as calcium, sodium and hydrogen inside living cells. These ion levels are found to undergo remarkable changes upon stimulation of quiescent cells with growth factors known to stimulate phosphoinositide breakdown. In serum-starved REF-52 fibroblasts, growth factors such as serum, vasopressin, or PDGF (platelet-derived growth factor) cause intracellular [Na+] to increase from about 4 mM to 8 mM. If mitogen treatment is combined with pharmacological depolarization of the membrane potential, repetitive [Ca2+]i spikes result in these rat fibroblasts. The mechanism of this oscillation has been investigated by light-flash release of intracellular messengers such as inositol 1,4,5-trisphosphate (Ins(1,4,5)P3), Ca2+, and diacylglycerol, as well as more traditional biochemical techniques. The key feedback pathway appears to be Ca2(+)-stimulation of phospholipase C production of Ins(1,4,5)P3.
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PMID:Imaging and manipulation of cytosolic ions and messengers during cell activation. 208 12

Nanosecond time-resolved tyrosinate fluorescence lifetimes were compared for oxytocin (OXT) and vasopressin (AVP) in propylene glycol. Long-lifetime tyrosinate fluorescence (LTF), characteristic of stable intramolecular hydrogen bond formation of the Tyr hydroxyl group, was present for OXT but not AVP in propylene glycol. The Tyr OH proton was also found to be labile for OXT but not AVP in DMSO by 1H-NMR. The spectroscopic data illustrate that the Tyr hydroxyl in OXT participates in an intramolecular hydrogen bond in certain receptor-simulating environments; the absence of potent LTF for [Ala5] OXT suggests that the Tyr hydroxyl of OXT forms an H-bond with the Asn5 carboxamide side-chain. The lability of the Tyr OH proton of OXT, but not AVP, is in accord with the biological activities of the peptides (OXT 100%, AVP 1%) in the rat uterus assay, suggesting that propylene glycol and DMSO mimic the environment at uterine receptors. 1H-NMR studies in DMSO demonstrate that for AVP there is a perpendicular-plate ring pairing interaction between the Tyr and Phe side-chains in which the hexagonal axis of the Tyr ring interacts with the face of the Phe ring. The present findings are discussed in terms of the proposed "cooperative model" for neurohypophysial hormone action.
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PMID:Tyrosinate fluorescence lifetimes for oxytocin and vasopressin in receptor-simulating environments: relationship to biological activity and 1H-NMR data. 217 14

In this study, the author intended to examine the validity of the inhaled hydrogen gas clearance method (i-H2) for determination of the hepatic blood flow (HBF), and also to show some applicabilities of the method in experimental animals and patients with liver diseases. Simultaneous determinations of HBF by i-H2 and electromagnetic flowmetry in rabbits revealed an excellent correlation between the values obtained by the two methods. Moreover, HBF in rabbits measured by i-H2 varied in parallel with that by thermocouple flowmetry or laser Doppler velocimetry after administration of norepinephrine, propranolol or glucagon. In carbon tetrachloride-treated rats, HBF measured by i-H2 correlated better with the severity of damage in the sinusoidal structure than the severity of hepatic cell injury or the serum levels of transaminases. HBF as determined by i-H2 was significantly decreased in acute hepatitis (AH), chronic inactive hepatitis (CIH), chronic active hepatitis (CAH), liver cirrhosis (LC) and fatty liver. Reduced HBF in AH returned to normal during recovery of the disease. The ratio of HBF in tumor/normal tissue was greater than 1.0 for hepatocellular carcinoma in contrast to the ratio of less than 1.0 for metastatic liver carcinoma. Propranolol caused a decrease in HBF by 31%, and vasopressin by 39% in patients with CIH or LC. In contrast, glucagon induced its increase by 65%, 35% and 17%, respectively, in patients with CIH, AH and LC.
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PMID:[Measurement of hepatic blood flow by the hydrogen gas clearance method. Experimental and clinical observations]. 236 96

In this paper, gastric blood flow in rats was measured with the laser-Doppler velocimetry method (the LDV method) to study about the tissue locus where its flow signal arises (spatial resolution). In the measurement throughout some 1 mm thickness of another nonperfused gastric wall interposed between the laser probe and gastric mucosal surface, its laser flow signal was 17% of the flow signal in the usual measurement. In the blood flow measurement with the LDV prove on the mucosal and the serosal surface of gastric wall, the laser flow signal on the mucosal surface was higher (p less than 0.05) than that on the serosal surface. These results suggested that the laser flow signal mainly arose from the tissue right under the laser probe, reflecting the total gastric blood flow of the gastric wall. In the regional blood flow measurement at corpus and antrum, the ratio between antral and corpus flow signals by the LDV method was similar to that between gastric mucosal blood flows at both sites by the hydrogen gas clearance technique. In the blood flow measurement after the intravenous infusion of each pentagastrin, isoproterenol, and vasopressin, flow signal of the LDV method could detect the each effect of these drugs on gastric mucosal blood flow as well as well as the hydrogen gas clearance technique. These results showed that the laser flow signal and gastric mucosal blood flow were mutually correlated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Evaluation of the laser-Doppler velocimetry method in the measurement of gastric blood flow in rats--spatial resolution]. 252 83

The plasma membrane composition of virtually all eucaryotic cells is established, maintained, and modified by the process of membrane recycling. Specific plasma membrane components are inserted by exocytosis of transport vesicles, and are removed by endocytosis of segments of the membrane in which particular proteins are concentrated. In the kidney collecting duct, vasopressin induces the cycling of vesicles that are thought to carry water channels to and from the apical plasma membrane of principal cells, thus modulating the water permeability of this membrane. In the intercalated cells of the collecting duct, hydrogen ion secretion is controlled by the recycling of vesicles carrying proton pumps to and from the plasma membrane. In both cell types, "coated" carrier vesicles are involved, but whereas clathrin-coated vesicles participate in water channel recycling, the vesicles in intercalated cells are coated with the cytoplasmic domains of proton pumps. Following a brief outline of membrane recycling in general, this review summarizes previous data on membrane recycling in the collecting duct and related transporting epithelia and discusses some selected points relating to the role of membrane recycling and cell-specific function in the collecting duct.
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PMID:Membrane recycling and epithelial cell function. 253 41

Measurement of pancreatic blood flow (PBF) is technically demanding. Although radiolabeled microspheres are considered the "gold standard" for PBF assessment, they have practical limitations. In the current study, H2 and xenon-133 gas clearance techniques were adapted to PBF measurement and compared to radiolabeled microsphere techniques. Simultaneous measurements of PBF were made using either hydrogen or xenon gas washout and radiolabeled microspheres. Measurements were made under basal, vasoconstricted (vasopressin 2U i.v. or nicotine 4 micrograms/kg/h) and stimulated (secretin 125 ng/kg/h or 2 U/kg i.v.) conditions (random order). Mean PBF was 26.9 +/- 5.3, 50.5 +/- 2.3 and 27.6 +/- 5.2 ml/min/100 g basally, 36.9 +/- 8.0, 90.1 +/- 18.9, and 81.7 +/- 14.5 ml/min/100 g in the stimulated state, and 24.2 +/- 7.8, 25.0 +/- 3.5, and 14.9 +/- 7.5 ml/min/100 g in the vasoconstricted state for hydrogen gas clearance, xenon gas clearance, and radiolabeled microspheres, respectively. The H2 clearance technique resulted in tissue trauma, was complicated by frequent electrode displacement, and correlated poorly (r2 = 0.36, p greater than 0.05) with microsphere values. In contrast, xenon clearance measurement had no apparent effect on the pancreas and correlated well (r2 = 0.83, p less than 0.01) with microsphere data. We conclude that xenon clearance offers an attractive, validated alternative to radiolabeled microspheres for measuring pancreatic blood flow.
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PMID:Comparison of gas clearance and radioactive microspheres for pancreatic blood flow measurement. 275 40


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