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  • Palytoxin  (7)
  • Tetanus  (6)
  • Antitoxin  (3)
  • Autoradiography  (3)
  • Depolarization  (3)
  • Peptides  (3)
  • Pharmacokinetics  (3)
Materialart
Erscheinungszeitraum
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 861 (1986), S. 165-176 
    ISSN: 0005-2736
    Schlagwort(e): (Erythrocyte membrane) ; (Na^+ + K^+)-ATPase ; Ligand binding ; Membrane permeability ; Ouabain ; Palytoxin
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Chemie und Pharmazie , Medizin , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 649 (1981), S. 481-486 
    ISSN: 0005-2736
    Schlagwort(e): (Erythrocyte) ; Hemolysis ; K^+loss ; Palytoxin
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Chemie und Pharmazie , Medizin , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 688 (1982), S. 486-494 
    ISSN: 0005-2736
    Schlagwort(e): (Erythrocyte) ; Amphotericin B ; Palytoxin ; Permeability
    Quelle: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Thema: Biologie , Chemie und Pharmazie , Medizin , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 334 (1986), S. 1-9 
    ISSN: 1432-1912
    Schlagwort(e): Depolarization ; Ion channels ; Phosphatidylinositol ; Inositol phosphates ; Voltage-dependence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have studied the accumulation of inositol phosphates (InsP) due to depolarization. A particulate preparation of rat brain was introduced to rule out transmitter activated mechanisms and to allow free access for drugs of high molecular weights. Potassium depolarization doubled InsP within a few minutes. InsP accumulation depended on time and K+ concentration, and was affected neither by tetrodotoxin nor by atropine. Radioactive metabolites co-eluted with inositol mono-phosphate and inositol bis-phosphate, whereas only minor amounts appeared with inositol tris-phosphate. The content in phosphatidylinositols was decreased. No evidence was found for the involvement of a neurotransmitter. Sea anemone toxin II (around 1 μmol/l), which keeps the Na+-channels open, promoted the InsP accumulation in an atropine-resistant manner. Tetrodotoxin prevented it when given before, and inhibited it when given after initiation by sea anemone toxin II. Moreover the K+ channel blockers 4-aminopyridine, dendrotoxin and tetraethylammonium all caused InsP accumulation. Palytoxin was by far the most potent promoter of InsP accumulation with a detection limit below 10 pmol/l, and displayed a unique bell-shaped concentration-effect correlation. Ouabain (3 μmol/l) and above) also elicited the InsP accumulation. The response to carbachol was not only inhibited completely by atropine, but also partially (more than 50%) by tetrodotoxin, which indicates the involvement of voltage-dependent sodium channels in the receptor-triggered InsP accumulation. Thus independent of the causative agent, depolarization promotes an InsP accumulation. We conclude that degradation of phosphatidylinositols is mediated not only by receptor occupation but also by a positive shift in membrane voltage.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 172-186 
    ISSN: 1432-1912
    Schlagwort(e): Bovine Serum ; Kininogen ; Peptides ; Enzymes ; Structure Evaluation ; Rinderserum ; Kininogen ; Peptide ; Enzyme ; Struktur-aufklärung
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung 1. Rinderserum ergab beim Umsatz mit Pepsin niedermolekulare, kininliefernde Spaltstücke. Das durch Fällung, Verteilung, Gelfiltration und Jonenaustausch-Chromatographie vorgereinigte Hydrolysat ließ sich durch Papierchromatographie in 2 Fraktionen trennen, auf die sich die kininliefernde Gruppierung im Verhältnis 5∶1 verteilte. 2. Beide kininliefernde Fraktionen waren resistent gegen Carboxypeptidase B, was gegen eine C-terminale Position der Kininsequenz spricht. Sie waren aktivierbar durch Trypsin, Pankreaskallikrein und auch Carboxypeptidase A. Trypsin in höherer Konzentration entwickelte aus der Hauptfraktion (L) Bradykinin, während mit Pankreaskallikrein, Carboxypeptidase A und kleinen Trypsinmengen Met-Lys-Bradykinin entstand. Die „direkte“ Aktivität der Fraktionen am Meerschweinchenileum lag bei maximal 1–2% der „indirekten“. 3. Aus der chromatographisch langsameren Hauptfraktion (L) wurde hoch-spannungselektrophoretisch ein einheitliches Minimalsubstrat für Kininogenasen isoliert. In seiner Aminosäurenanalyse entsprach es dem aus gereinigtem Rinderserum-Kininogen isolierten Hauptpeptid PKFL; auch beim Edman-Abbau ergaben sich keine Unterschiede. 4. Die früher für gereinigtes Kininogen beschriebenen Sequenzen sind also auch für Gesamtserum repräsentativ. Hinweise auf andersartige Peptide, insbesondere auf solche mit der Kininsequenz in C-terminaler Position, ergaben sich nicht.
    Notizen: Summary 1. Peptic treatment of bovine serum produced kinin yielding substances of low molecular weight. The hydrolyzate was purified by precipitation, partition, gel filtration and ion exchange chromatography. Subsequent paper chromatography revealed two fractions with a 5∶1 distribution of the kinin-yielding property. 2. Both kinin-yielding fractions were resistant to carboxypeptidase B, a finding which argues against a C-terminal position of the kinin sequence. They could be activated by trypsin, pancreatic kallikrein, and carboxypeptidase A. Higher concentrations of trypsin released bradykinin from the main fraction (L), whereas pancreatic kallikrein, carboxypeptidase A and low amounts of trypsin produced met-lysbradykinin. The “direct” activity of the fractions as measured on the guinea pig ileum was no more than 1–2% of the “indirect” activity. 3. A homogeneous minimal substrate was isolated from the chromatographically slower fraction L by high voltage electrophoresis. With respect to amino acid analysis and Edman degradation, it could not be distinguished from the peptide PKFL isolated from purified bovine kininogen. 4. Therefore, the sequences described previously in purified kininogen are also representative for whole serum. Evidence for different peptides, especially with the kinin sequence in C-terminal position, was not found.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 276 (1973), S. 327-340 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus Toxin ; Pharmacokinetics ; Central Nervous System ; Iodine Labelling ; Receptors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to understand the symptomatology of generalized tetanus from the pharmacokinetics of the toxin, 125I-labelled toxin was injected i.v. in rats without and with antitoxin. 1. After a few hours latency, brain stem and spinal cord concentrate radioactive material up to the third day. The decline of radioactivity is very slow, semilogarithmic, and can be followed up to the 24th day after injection. In contrast, forebrain and cerebellum do not bind measurable radioactivity. Less than 1% of the radioactivity injected is found in the CNS. 2. The symptoms of tetanus start some time after the bulk of labelled toxin has been taken up by the CNS. They cease before all radioactivity has left it. 3. Antitoxin, given simultaneously, prevents the onset of symptoms and the uptake of radioactivity by the CNS. When given 10 h after labelled toxin, it nearly abolishes the fixation and still prevents the onset of symptoms. When given 48 h after toxin, it is nearly ineffective in both respects. Antitoxin first delays, then enhances the elimination of labelled toxin from the blood. 4. Labelled antitoxin is not enriched in the CNS. 5. The uptake of radioactivity into various parts of spinal cord corresponds well to their relative content in grey matter. 6. The pharmacokinetic behaviour of 125I-toxoid resembles that of toxin. However, in order to get measurable fixation to the CNS at least 50 times higher amounts are to be applied. It is concluded that the barrier between blood and CNS is practically impermeable to tetanus toxin. The results can be harmonized best with the assumption that generalized tetanus is nothing else than a multiple local tetanus.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 133-138 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus ; Botulism ; Acetylcholine ; Nerve tissue ; Cell cultures
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Primary nerve cell cultures derived from embryonic rat central nervous system form [3H]ACh from exogenous [3H]Ch, and release it upon potassium depolarization. Pretreatment of the cultures with botulinum-A toxin or tetanus toxin diminishes the cellular accumulation of [3H]ACh. Poisoning the cultures during the period of [3H]Ch uptake fails to lower [3H]ACh formation. Dependent on dosage, both toxins suppress the release of [3H]ACh upon potassium depolarization. Heat-denaturated toxins as well as tetanus toxin preincubated with tetanus antitoxin were without effect.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 323 (1983), S. 269-275 
    ISSN: 1432-1912
    Schlagwort(e): Palytoxin ; Tetraphenylphosphonium ; Depolarization ; Binding ; Borate ; Calcium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Palytoxin in concentrations as low as 10−11 to 10−12 M promotes the outflow of the lipophilic [3H]-tetraphenylphosphonium ion from particulate brain cortex of guinea-pigs and rats, and from preloaded crude synaptosomes of rats, which indicates depolarization. The outflow is not influenced by tetrodotoxin or the calcium channel blocker nimodipin, or by substitution of choline for Na+ ions. It is increased by Ca2+ and by borate, the latter interacting with the toxin itself. To assess the fixation of palytoxin to biological membranes, a binding step was installed before the depolarization step. Palytoxin binds to membranes from rat brain, liver, kidney, human and dog erythrocytes, and to a lesser degree to liposomes made from rat brain or erythrocyte lipids. Binding is reversible. It is decreased by mild physical pretreatments of crude synaptosomes. Palytoxin binding is increased in the presence of micromolar concentrations of Ca2+ or borate. It is concluded that the potentiation of palytoxin actions by Ca2+ or borate is at least partially due to the promotion of its binding.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 319 (1982), S. 101-107 
    ISSN: 1432-1912
    Schlagwort(e): Palytoxin ; Ouabain ; Erythrocytes ; Permeability ; ATPase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary 1. Palytoxin in concentrations as low as 1 pM raises the potassium permeability of rat, human and sheep erythrocytes, and the sodium permeability of human erythrocytes. The release of potassium or sodium from human cells also occurs when extracellular sodium is replaced by choline. 2. Ouabain inhibits the release due to palytoxin of potassium ions from human, sheep and rat erythrocytes, and also the release of sodium ions from human cells. The glycoside effect is specific since a) it is already prominent with 5×10−8 M ouabain b) rat erythrocytes are less sensitive than human cells to ouabain c) potassium release due to amphotericin B or the Ca2+ ionophore A23187 is not influenced by ouabain and d) dog erythrocytes are resistant to palytoxin as well as to ouabain. 3. Palytoxin has no direct influence on the Na+, K+-ATPase. It inhibits the binding of [3H]ouabain to erythrocyte membranes within the same concentration range as unlabelled ouabain. It partially displaces bound [3H]ouabain, and partially inhibits the inactivation of erythrocyte ATPase by the glycoside. Depletion of ATP or of external Ca2+ renders the cells less sensitive to palytoxin. Nevertheless inhibition by ouabain can be still demonstrated with human cells whose ATP stores had been largely exhausted, and also in the absence of external Ca2+. 4. Palytoxin decreases the surface tension at the air-water interface. We assume that the formation of nonspecific pores by palytoxin is linked with its surface activity. Further experiments should demonstrate whether ouabain prevents the binding of palytoxin to erythrocytes (“receptor hypothesis”), or whether an ouabain-sensitive hydrolysis of trace amounts of ATP (“metabolic hypothesis”) promotes the palytoxin effect.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 325 (1984), S. 85-87 
    ISSN: 1432-1912
    Schlagwort(e): Na+, K+-ATPase ; Palytoxin ; Ouabain ; Kidney ; Erythrocyte
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Hog kidney Na+, K+-ATPase, purified to the microsomal stage and activated with detergent, binds palytoxin, as shown by the nearly complete competition of the toxin with 3H-ouabain. The K i-values of palytoxin, but not of ouabain, depend on the protein concentration; this indicates additional binding sites for the toxin on kidney membranes. — Palytoxin inhibits the enzymatic activity of the detergent-activated preparation nearly completely (IC50 8·10−7 mol/l). Inhibition of ATPase activity and of ouabain binding are promoted by borate, a known activator of palytoxin. — Palytoxin also inhibits the Na+, K+-ATPase of erythrocyte ghosts in the same dose range. The data are discussed in context with the hypothesis (Chhatwal et al. 1983) that palytoxin raises the cellular permeability by altering the state of Na+, K+-ATPase or its environment.
    Materialart: Digitale Medien
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