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  • Palytoxin  (7)
  • Calcium  (5)
  • Botulinum A toxin  (4)
  • Peptides  (3)
  • 1
    ISSN: 0014-5793
    Keywords: Botulinum A toxin ; Chain, heavy ; Chain, light ; Chromaffin cell, permeabilized ; Exocytosis
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 688 (1982), S. 486-494 
    ISSN: 0005-2736
    Keywords: (Erythrocyte) ; Amphotericin B ; Palytoxin ; Permeability
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Biomembranes 649 (1981), S. 481-486 
    ISSN: 0005-2736
    Keywords: (Erythrocyte) ; Hemolysis ; K^+loss ; Palytoxin
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 316 (1981), S. 135-142 
    ISSN: 1432-1912
    Keywords: Tetanus toxin ; Botulinum A toxin ; Choline ; Gangliosides ; Fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tetanus toxin and, to a lesser degree, botulinum A toxin inhibit partially and noncompetitively the uptake of [3H]choline into a crude synaptosomal fraction from rat brain cortex. Botulinum toxin acts by its neurotoxin content. The effect is not due to nonspecific synaptosomal damage by the toxins as shown by the lactate dehydrogenase occlusion test, by the absence of swelling and by the preservation of choline stores. The ratio between [3H]acetylcholine and [3H]choline was decreased by both toxins. Inhibition by either toxin depends strongly on the temperature and duration of incubation, and is preceded by an initial latency period. The effect of tetanus toxin, once manifest, is largely resistant against antitoxin. It is not significantly diminished by pretreatment of the synaptosomes with V. cholerae neuraminidase. Fixation of 125I-tetanus toxin proceeds fast, is largely independent of temperature and is diminished by pretreatment of the synaptosomes with neuraminidase. Thus only some of the fixation sites, and not the long-chain gangliosides, are required for the effects of tetanus toxin. A slow, temperature-sensitive process links the fixation with the action. In contrast to rat synaptosomes the chicken preparation is more sensitive to botulinum A than to tetanus toxin, which reflects the differences in sensitivity between live birds and rodents. Our data underline the similarities between the effects of tetanus and those of botulinum A toxin. Their dependence on time and temperature, the time dependence of efficacy of antitoxin, and the concordance in species specificity indicate that the in vitro system mirros some crucial features of poisoning of isolated organs and live animals.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 316 (1981), S. 143-148 
    ISSN: 1432-1912
    Keywords: Tetanus toxin ; Botulinum toxin ; Acetylcholine ; Calcium ; Brain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Slices or particles from rat forebrain cortex were preloaded with [3H]choline, and the release of [3H]acetylcholine was evoked with potassium ions in a superfusion system. Release depended on the presence of calcium. 1. Incubation of the preloaded tissue preparation for 2 h with tetanus or botulinum A toxin did not change the [3H]acetylcholine content or the ratio [3H]acetylcholine/[3H]choline. Tetanus toxin diminished, dependent on dose and time, the release of [3H]acetylcholine evoked by 25 mM K+. It was about ten times more potent than botulinum A toxin. The effect of botulinum toxin was due to its neurotoxin content. Raising the potassium concentration partially overcame the inhibition by the toxins. Hemicholinium-3, applied to preloaded slices, left the subsequent [3H]acetylcholine release unchanged. Pretreatment of particles with neuraminidase diminished the content of long-chain gangliosides to the detection limit. Such particles remained fully sensitive to tetanus toxin, and at least partially sensitive to botulinum A toxin. 2. The potassium or sea anemone toxin II stimulated uptake of 45Ca2+ into cortex synaptosomes or particles was not inhibited by either toxin. Both toxins appear to impede the Ca2+-dependent mobilization of an easily releasable acetylcholine pool, without inhibiting the transmembranal calcium fluxes.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 323 (1983), S. 261-268 
    ISSN: 1432-1912
    Keywords: Palytoxin ; Erythrocyte ; Membrane ; Na+, K+-ATPase ; Calcium ; Ouabain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Palytoxin increases the permeability of human erythrocytes and their resealed ghosts. To elucidate its mode of action the activation by ATP and Ca2+, the inhibition by ouabain, and the changes in permselectivity have been studied: 1. Depletion of cells from ATP considerably depresses their sensitivity towards palytoxin. Ouabain prevents the actions of the toxin, however, with different inhibition characteristics in normal and depleted cells. The concentration of palytoxin required to raise the K+ permeability is higher in ghosts than in erythrocytes. The sensitivity is restored by incorporating ATP which can be partially substituted by ADP and GTP but not by AMP, Pi, β-γ-methylene adenosine 5′-triphosphate or the chromium (III) complex of ATP. Ouabain inhibits the K+ release from resealed ghosts in the presence as well as absence of ATP. Ouabain also inhibits the palytoxin-triggered Na+ and choline efflux into Na+ medium, as well as the Na+, K+ and choline efflux into choline medium. Phosphate promotes the inhibitory action of ouabain. Incorporated vanadate or Mg2+ do not change the sensitivity of ghosts toward palytoxin. 2. External calcium down to 10 μM potentiates the action of palytoxin in ghosts resealed with or without ATP. In contrast to calcium ionophore A23187, palytoxin does not raise the influx of Ca2+. 3. Palytoxin triggers the formation of small pores in resealed ghosts. The efflux into Na+ medium decreases in the order K+≧Na+〉[3H]choline≫[14C]inositol〉[14C]sucrose, [3H]inulin≅0. Our data suggest that palytoxin, once bound to erythrocyte membranes, transforms the sodium pump, or its functional vicinity, into a pore allowing the passive transport of small ions. This process is assisted by ATP from inside whereas Ca2+ promotes from the outside the efficacy of palytoxin.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 319 (1982), S. 101-107 
    ISSN: 1432-1912
    Keywords: Palytoxin ; Ouabain ; Erythrocytes ; Permeability ; ATPase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 252-270 
    ISSN: 1432-1912
    Keywords: Peptides ; Bee Venom ; Mast Cells ; Histamine ; Vascular Permeability ; Peptide ; Bienengift ; Mastzellen ; Histamin ; Gefäßpermeabilität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bienengift enthält neben dem universell zellschädigenden Melittin und der über Lysolecithinbildung wirksamen Phospholipase A ein drittes mastzelldegranulierendes (MCD-)Peptid. Seine Isolierung gelingt durch Kombination von Gelfiltration an Sephadex G 50 mit Ionenaustauschchromatographie an Carboxymethylcellulose und an Amberlite IRC-50. MCD-Peptid ist stark basisch (Isoelektrischer Punkt um pH 12). Sein minimales Molekulargewicht errechnet sich aus der Aminosäurenanalyse zu 2593. Das Peptid besteht aus 22 Aminosäuren, darunter 4 Halbcystinen. Es liegt in zwei verschiedenen Ladungszuständen vor, die sich bei Papierchromatographie, Papierelektrophorese und Aminosäurenanalyse einheitlich verhalten. MCD-Peptid ist an isolierten Rattenmastzellen (Histaminfreisetzung) und am Mesenterialhäutchen der Ratte (Mastzelldegranulation) etwa wirkungsgleich mit dem synthetischen Histaminliberator Compound 48/80. Melittin wirkt ca. 100- bzw. 10 mal schwächer und zeichnet sich überdies durch eine sehr flache Dosis-Wirkungsbeziehung bei der Histaminfreisetzung aus. Der Rattenblutdruck wird durch MCD-Peptid und Compound 48/80 in quantitativ und qualitativ vergleichbarer Weise gesenkt. Zwischen beiden Substanzen besteht kreuzweise Tachyphylaxie. Die Permeabilität der Hautgefäße der Ratte für zirkulierendes Evans-Blau steigt bei intracutaner Applikation von MCD-Peptid und Compound 48/80. Beide Substanzen sind hier stärker wirksam als Melittin. Die Hautgefäße des Kaninchens sprechen jedoch auf MCD-Peptid schwächer an als auf Melittin und Compound 48/80. Die Ratte reagiert auf i.v. Injektion von 0,5–10 mg/kg MCD-Peptid mit massiver Hyperämie der Acren. Eine kurzdauernde Spastik der Extremitäten weist auf einen zusätzlichen Angriff am motorischen System hin.
    Notes: Summary Bee venom contains three agents which can produce mast cell degranulation. Melittin is a universally acting surfactant; phospholipase A releases the mastocytolytic lysolecithin. A third mast cell degranulating (MCD) peptide has been isolated by gel filtration on Sephadex G 50, followed by chromatography on carboxymethylcellulose, and, finally, on Amberlite IRC-50. MCD-peptide is strongly basic (isoelectric point near pH 12). From the amino acid analysis, a minimum molecular weight of 2593 has been calculated. MCD-peptide consists of 22 amino acids, among them 4 halfcystine residues. It can be obtained in two fractions differing by charge, which appear homogeneous, however, on paper chromatography, paper electrophoresis, and amino acid analysis. When tested on isolated mast cells or on mesentery tissue of rats, MCD-peptide is equiactive with compound 48/80. On the other hand, melittin is 100 times less potent than compound 48/80 on the former tissue and 10 times less potent on the latter; moreover, the dose-response-relation of histamine release is flatter with melittin. MCD-peptide and compound 48/80 depress the blood pressure of rats in a quantitatively and qualitatively similar manner. Crossed tachyphylaxis has been demonstrated. Both substances increase the capillary permeability of rat skin upon intracutaneous injection. Melittin is less active on rat skin vessels. The skin capillaries of rabbits are, however, more sensitive to melittin and compound 48/80 than to MCD-peptide. MCD-peptide (0.5–10 mg/kg i.v.) produces in rats an extreme cyanosis of the acra. A short lasting spasm of the extremities points to an additional effect on the motor system of rats.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 172-186 
    ISSN: 1432-1912
    Keywords: Bovine Serum ; Kininogen ; Peptides ; Enzymes ; Structure Evaluation ; Rinderserum ; Kininogen ; Peptide ; Enzyme ; Struktur-aufklärung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: 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.
    Notes: 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.
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  • 10
    ISSN: 1432-1912
    Keywords: Tetanus toxin ; Botulinum A toxin ; Neurotransmitter ; Uptake ; Release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of tetanus toxin and botulinum A toxin on the uptake and evoked release of various neurotransmitters were studied using particles from rat forebrain, corpus striatum and spinal cord. 1. Uptake. Tetanus toxin partially inhibits the uptake of glycine and choline into spinal cord synaptosomes. The effect on glycine uptake becomes statistically significant after a lag period of 60\2-120 min. It is no longer present when the toxin is heated, antitoxin-treated or toxoided. The inhibition by botulinum A toxin of choline uptake into spinal cord synaptosomes is weak but measurable, that of glycine uptake is at the borderline of detection. The uptake of GABA into forebrain cortex synaptosomes is slightly inhibited by tetanus toxin but hardly by botulinum A toxin. The effects of tetanus toxin and botulinum A toxin on the uptake of noradrenaline into striatal synaptosomes are negligible. 2. Release. Tetanus toxin inhibits the potassium (25 mM) evoked release of radioactivity from rat forebrain cortex particles preloaded with labelled neurotransmitters. The sensitivity decreases in the following order: Glycine 〉 GABA \2〉 acetylcholine. The toxin also inhibits the release of radioactivity from striatal particles preloaded with labelled noradrenaline. It is always 10\2-50 times more potent on spinal cord than on brain particles. The sensitivity of the evoked release from the spinal cord decreases in the order glycine 〉 GABA 〉 acetylcholine 〉 noradrenaline. The toxin is identical with the causative agent because toxin-antitoxin complexes, toxoid and heated toxin do not influence the release from particles preloaded with glycine (spinal cord), GABA (forebrain) and noradrenaline (striatum). Botulinum toxin resembles tetanus toxin by its ability to diminish the release of radioactivity from preloaded forebrain (acetylcholine 〉 GABA), striatal (noradrenaline), or spinal cord (glycine) particles. The botulinum toxin effect on the striatum (noradrenaline) and on the spinal cord (glycine) is due to its neurotoxin content. The identity of the toxin and the causative agent has been established by preheating and preincubation with antitoxin. It is proposed that a) tetanus and, however to a much lesser degree, botulinum A toxin act in a basically similar manner on a process underlying the function of synapses in general, and b) the pronounced sensitivity of glycine and GABA release from spinal cord, together with the axonal ascent of tetanus toxin, may be crucial in the pathogenesis of tetanus.
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