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  • Tetanus  (6)
  • Depolarization  (3)
  • Kidney  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Depolarization increases inositolphosphate production in a particulate preparation from rat brain (1986)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 334 (1986), S. 1-9 
    Details
    ISSN: 1432-1912
    Keywords: Depolarization ; Ion channels ; Phosphatidylinositol ; Inositol phosphates ; Voltage-dependence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498733
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  • 2
    Electronic Resource
    Electronic Resource
    The renal handling of polybasic drugs (1977)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 300 (1977), S. 57-66 
    Details
    ISSN: 1432-1912
    Keywords: Aminoglycoside ; Gentamicin ; Kidney ; Electron microscopic autoradiography ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Upon intravenous injection of 3H-gentamicin in rats, radioactivity in serum rapidly declined to 3% of total within 1 h. Kidneys accumulated a constant amount (14%) of the injected radioactivity between 2 and 6 h after injection. In mice, simultaneous or prior application of unlabeled gentamicin (10 mg/kg) diminished the renal concentration of 3H-gentamicin, and aprotinin (10 mg/kg) was able to compete with labeled aprotinin. Aprotinin did not diminish the renal accumulation of gentamicin and vice versa. However, since 10 mg/kg aprotinin raised also the plasma concentrations of both 3H-gentamicin and 125I-aprotinin, the evidences resulting from these experiments are limited. Mouse kidney cortex was processed for light and electron microscopic autoradiography at different times following i.v. injection of 3H-gentamicin. Gentamicin enters the apical part of proximal tubule cells. Initially, brush border and basement membrane labeling is prominent, whereas lysosomes appear as intense and prevalent stores 20 min or later after injection. Fractionation of 3H-gentamicin loaded kidneys showed a similar distribution pattern of radioactivity and the lysosomal marker β-galactosidase. The same was true when the crude lysosomal fraction was subjected to density gradient centrifugation, which corroborates the microscopical findings. Radioactivity is partially bound to lysosomal structures, for repeated freezing of loaded lysosomes left 35% of radioactivity particle-bound. It is concluded that both gentamicin and peptides are handled in a similar manner by adsorption, followed by endocytosis and lysosomal sequestration in proximal tubule cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505080
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  • 3
    Electronic Resource
    Electronic Resource
    Suppression of 3H-acetylcholine release from primary nerve cell cultures by tetanus and botulinum-A toxin (1978)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 303 (1978), S. 133-138 
    Details
    ISSN: 1432-1912
    Keywords: Tetanus ; Botulism ; Acetylcholine ; Nerve tissue ; Cell cultures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00508058
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  • 4
    Electronic Resource
    Electronic Resource
    Action and binding of palytoxin, as studied with brain membranes (1983)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 323 (1983), S. 269-275 
    Details
    ISSN: 1432-1912
    Keywords: Palytoxin ; Tetraphenylphosphonium ; Depolarization ; Binding ; Borate ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00497673
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  • 5
    Electronic Resource
    Electronic Resource
    Palytoxin binds to and inhibits kidney and erythrocyte Na+, K+-ATPase (1984)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 325 (1984), S. 85-87 
    Details
    ISSN: 1432-1912
    Keywords: Na+, K+-ATPase ; Palytoxin ; Ouabain ; Kidney ; Erythrocyte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00507059
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  • 6
    Electronic Resource
    Electronic Resource
    Histoautoradiography of central nervous system in rats with generalized tetanus due to 125I-toxin (1977)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 301 (1977), S. 135-138 
    Details
    ISSN: 1432-1912
    Keywords: Tetanus ; Toxin ; Axonal transport ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rats were injected i.v. with 125I-tetanus toxin. In autoradiographs of the spinal cord radioactivity was found over the pericarya and in the surroundings of the motoneurones whereas grain density was less over their nuclear region. In addition, pericarya in the lateral horn of the thoracic region and also the bipolar cells of the spinal ganglia contained radioactivity. The central part and the dorsal horns of spinal cord, and the white substance did not show any appreciable radioactivity. Within the medulla oblongata, clusters of large cells representing motor nuclei, as well as some fibre tracts close to them, contained 125I. Forebrain and cerebellum remained free. According to its histoautoradiographic appearance, generalized tetanus can be described best as a combination of multiple local tetani.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00501428
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  • 7
    Electronic Resource
    Electronic Resource
    Electrophysiological and neurobiochemical evidence for the blockade of a potassium channel by dendrotoxin (1985)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 330 (1985), S. 77-83 
    Details
    ISSN: 1432-1912
    Keywords: Dendrotoxin ; Potassium channel ; Nerve fibre ; Depolarization ; GABA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of dendrotoxin (DTX), a toxic peptide from Dendroaspis angusticeps venom, were studied electrophysiologically on peripheral frog nerve fibres, and biochemically on large synaptosomes from rat brain. 1. On nerve fibres, DTX reduced the amplitude and prolonged the duration of the action potential; even at 0.1 nmol/l DTX produced significant effects. Maximum block of potassium currents occurred at about 30 nmol/l. Turning on of the remaining current was slowed. Reversibility was incomplete. The reduction of potassium currents was between 31% and 85% at 85 nmol/l DTX (n=8). The remainder appeared to be resistant to DTX. Sodium channels were not affected. 2. On large synaptosomes DTX (above 1 nmol/l) produced a slight depolarization, indicated by an outward shift of the lipophilic cation tetraphenylphosphonium, and promoted the release of radioactivity after preloading with [3H] GABA. DTX had similar potency but lower efficacy in this respect than sea anemone toxin II (ATX II). In contrast to the effects of ATX II, those due to DTX were only partially inhibited by tetrodotoxin. The actions of 4-aminopyridine resembled those of DTX, but the latter was about 500 times more potent. The electrophysiological data provide direct evidence for blockade of a potassium channel by DTX. This action is sufficient to explain the biochemical observations, although additional effects on synaptosomes cannot be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00499898
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  • 8
    Electronic Resource
    Electronic Resource
    A rapid and simple radioimmunological procedure for measuring low concentrations of tetanus antibodies (1973)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 276 (1973), S. 321-326 
    Details
    ISSN: 1432-1912
    Keywords: Tetanus ; Antibodies ; Radioimmunological Measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A radioimmunological assay procedure allows the measurement of small amounts of tetanus antibodies; it should also be applicable to antibodies against other soluble antigens. It is based on the competition between dissolved and solid phase antibodies for labelled antigen. In the range of experimental error, the same antibody titers are found with the radioimmunological and with the mouse protection test. The detection limit is in the range of 0.001 IU/ml. The reaction conditions allow the determination of antibodies in multiple samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00499886
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  • 9
    Electronic Resource
    Electronic Resource
    125I-labeled neurotoxin from clostridium botulinum A: Preparation, binding to synaptosomes and ascent to the spinal cord (1974)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 281 (1974), S. 47-56 
    Details
    ISSN: 1432-1912
    Keywords: Botulinum A ; Tetanus ; Neurotoxin ; Hemagglutinin ; Iodine Labeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Labeling of crystalline botulinum A toxin has been done with 125I by aid of the chloramine T method. The neurotoxic component is well preserved, whereas the hemagglutinin undergoes physicochemical alterations. Neither with labeled nor with unlabeled toxin, hemagglutinating power parallels the main protein peak. 2. Neurotoxin, homogeneous in gel filtration, is bound to synaptosomes from rat brain. Cold toxin competes with labeled toxin, and antitoxin or neuraminidase partially remove the bound neurotoxin. 3. Upon intramuscular injection, some radioactivity is recovered in the respective parts of the spinal cord. Antitoxin prevents the ascent. The similarities between tetanus and botulinum A neurotoxins are stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500611
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  • 10
    Electronic Resource
    Electronic Resource
    Affinity chromatography of tetanus toxin, tetanus toxoid, and botulinum a toxin on synaptosomes, and differentiation of their acceptors (1976)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 293 (1976), S. 1-9 
    Details
    ISSN: 1432-1912
    Keywords: Tetanus ; Botulism ; Tetanus toxoid ; Affinity chromatography ; Synaptosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 125I-labelled tetanus toxin and 125I-labelled botulinum A neurotoxin are known to be specifically bound to brain synaptosomes. In order to discriminate between active toxin and inactive admixtures present in the starting material or arising during isodination, synaptosome columns were prepared using bromacetylcellulose and/or kieselgur (Celite®) as carriers. Both types of columns adsorb the toxins from low ionic strength medium and release them if the pH and ionic strength are raised. Botulinum toxin was eluted with lower ionic strength than tetanus toxin, and could be freed from nontoxic admixtures. Analysis by affinity chromatography disclosed partially toxoided tetanus toxin in both labelled and unlabelled toxin samples. High concentrations of formaldehyde (0.5%) destroyed both toxicity and affinity to the synaptosomes of tetanus toxin. Low concentrations of formaldehyde (0.05%) yielded a derivative of low toxicity which was still, however less firmly, bound to synaptosomes. Tetanus and botulinum toxin differ by their acceptors. Whereas unlabelled botulinum toxin is unable to compete with labelled tetanus toxin, unlabelled tetanus toxin slightly competes with botulinum toxin. Both labelled toxins display anomalous binding behaviour in that they cannot be displaced completely even with a large excess of unlabelled toxin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00498864
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