Search results for "INTRAC"
showing 10 items of 1509 documents
Isoform specificity of cardiac glycosides binding to human Na+,K+-ATPase α1β1, α2β1 and α3β1
2009
Abstract Cardiac glycosides inhibit the Na + ,K + -ATPase and are used for the treatment of symptomatic heart failure and atrial fibrillation. In human heart three isoforms of Na + ,K + -ATPase are expressed: α 1 β 1 , α 2 β 1 and α 3 β 1 . It is unknown, if clinically used cardiac glycosides differ in isoform specific affinities, and if the isoforms have specific subcellular localization in human cardiac myocytes. Human Na + ,K + -ATPase isoforms α 1 β 1 , α 2 β 1 and α 3 β 1 were expressed in yeast which has no endogenous Na + ,K + -ATPase. Isoform specific affinities of digoxin, digitoxin, β-acetyldigoxin, methyldigoxin and ouabain were assessed in [³H]-ouabain binding assays in the abse…
Isolation of endothelin A receptor from bovine lungs.
1995
We isolated endothelin receptor A (ET A ) from bovine lungs in a single-step purification procedure using antibodies raised against synthetic peptides that correspond to extra- and intracellular domains of the rat bradykinin receptor. Two receptor species of 55 and 35 kDa were isolated and subjected to N-terminal microsequencing. The difference between the observed and expected molecular weight species suggests that bovine ET A receptor is glycosylated.
Influence of intracellular sodium concentration on calcium influx in isolated guinea pig auricles.
1969
Red blood cell sodium and potassium after hydrochlorothiazide.
1981
In six of seven healthy males 6 days of hydrochlorothiazide (HCT), 50 mg twice daily, without potassium supplements resulted in a rise in red blood cell (RBC) sodium concentration. Serum potassium concentration fell in all subjects. Four days after discontinuing HCT, intracellular sodium and extracellular potassium concentrations had normalized. Throughout the evaluation period the course of mean relative intracellular sodium was almost a mirror image of mean relative extracellular potassium. Thus, either the decline of serum potassium or of HCT (because of its inhibitory effect on Na-K-ATPase activity) might have diminished Na-K-ATPase–dependent active RBC sodium efflux with a resultant ri…
Experiments on the metyrapone reducing microsomal enzyme system.
1970
The formation of reduced metyrapone [2-methyl-1.2-bis-(3-pyridyl)-1-propanol] from metyrapone [2-methyl-1.2-bis-(3-pyridyl)-1-propanone] in the liver has been studied. Reduced metyrapone appeared as the main metabolite of metyrapone in the isolated perfused rat liver. Experiments on the intracellular distribution of the metyrapone reducing activity revealed that metyrapone reductase is mainly localized in the microsomal fraction. In the 105,000 × g supernatant only a little activity was found.
Effects of Kaempferol and Myricetin on Inducible Nitric Oxide Synthase Expression and Nitric Oxide Production in Rats
2010
Abstract: When administered as drugs or consumed as food components, polyphenolic compounds synthesized in plants interfere with intracellular signal transduction pathways, including pathways of nitric oxide synthase expression. However, effects of these compounds in vivo do not always correlate with nitric oxide synthase-inhibiting activities revealed in experiments with cultured cells. The initial goal of this work was to compare effects of flavonoids kaempferol and myricetin on inducible nitric oxide synthase mRNA and protein expression monitored by real-time RT-PCR and immunohistochemistry and to evaluate the impact of these effects on nitric oxide production in rat organs measured by …
Docosahexaenoic acid and other fatty acids induce a decrease in pHiin Jurkat T-cells
2003
Docosahexaenoic acid (DHA) induced rapid (t1/2=33 s) and dose-dependent decreases in pHi in BCECF-loaded human (Jurkat) T-cells. Addition of 5-(N,N-dimethyl)-amiloride, an inhibitor of Na+/H+ exchanger, prolonged DHA-induced acidification as a function of time, indicating that the exchanger is implicated in pHi recovery. Other fatty acids like oleic acid, arachidonic acid, eicosapentaenoic acid, but not palmitic acid, also induced a fall in pHi in these cells. To assess the role of calcium in the DHA-induced acidification, we conducted experiments in Ca2+-free (0% Ca2+) and Ca2+-containing (100% Ca2+) buffer. We observed that there was no difference in the degree of DHA-induced transient ac…
Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyte-endothelial cell interactionsin vivo
2003
The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang-II)-induced leukocyte–endothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used. A 60 min superfusion with 1 nM Ang-II induced a significant increase in the leukocyte–endothelial cell interactions that were completely inhibited by 1 μM uvariopsine cosuperfusion. A lower dose of 0.1 μM significantly reduced Ang-II-induced leukocyte adhesion by 75%. When Ang-II was cosuperfused with 1 and 0.1 μM stephenanthrine, Ang-II-induced leukocyte responses were significantly …
Effects of nitric oxide donors on cardiac contractility in wild-type and myoglobin-deficient mice
2002
1. The effects of the nitric oxide (NO) donors S-nitroso-N-acetylpenicillamine (SNAP), sodium(Z)-1-(N,N-diethylamino)diazen-1-ium-1,2-diolate (DEA-NONOate), and (Z)-1-[N-(2-Aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NONOate) on force of contraction (F(c)) were studied in atrial and ventricular muscle strips obtained from wild-type (WT) and myoglobin-deficient (myo(-/-)) mice. 2. SNAP slightly reduced F(c) in preparations from WT mice at concentrations above 100 microM; this effect was more pronounced in myo(-/-) mice. 3. DEA-NONOate reduced F(c) in preparations from myo(-/-) mice to a larger extent than those from WT mice. 4. DETA-NONOate reduced F(c) in preparations…