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  • Autoradiography  (3)
  • Peptides  (3)
  • Pharmacokinetics  (3)
Materialart
Erscheinungszeitraum
Schlagwörter
  • 1
    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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  • 2
    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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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 261 (1968), S. 252-270 
    ISSN: 1432-1912
    Schlagwort(e): Peptides ; Bee Venom ; Mast Cells ; Histamine ; Vascular Permeability ; Peptide ; Bienengift ; Mastzellen ; Histamin ; Gefäßpermeabilität
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 270 (1971), S. 1-9 
    ISSN: 1432-1912
    Schlagwort(e): Melittin ; Peptides ; Venoms ; Hemolysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The hexacosapeptide melittin I, which is the main toxin of bee venom, has been synthesized by Lübke and Schröder. In addition, the following derivatives have been prepared which are probably also present in bee venom: melittin II (which differs by one serine), and N1-formylated melittin I and II. In pharmacological tests, the four synthetic peptides were qualitatively indistinguishable from natural melittin as prepared from bee venom. Theyhemolyzed rabbit erythrocytes with a flat dose-response curve. Melittin I exerted 92% of the activity of the natural substance, the three other peptides 90, 61 and 52% respectively.-Theirsurface activity was between 86 and 96% of that of the natural material.-In contrast to our previous reports, no differences were found in onset, degree and duration of the shortlastinghypotensive action in rabbits.-Toxicity (LD 50, mice) was about 4 mg/kg for natural melittin and for the synthetic melittins I and II. The toxicity of formylated melittins was not very different.-The five compounds caused a slow and prolongedcontraction of the guinea-pig ileum which led to tachyphylaxis. Peptide mapping confirmed the identity between the main compound of natural melittin and synthetic melittin I. The peptide pattern of synthetic melittin II is different and is further modified by the presence of the N-formyl group. Our findings leave no doubt as to the identity between the bulk of natural melittin and melittin I. They corroborate the presence in natural melittin of small amounts of N1-formylated melittin I. The pharmacological similarities to synthetic melittin II and N1-formylated melittin II (which have not yet been identified in the venom) argue for a broader structural basis of the melittins as a group.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 301 (1977), S. 135-138 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus ; Toxin ; Axonal transport ; Autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 276 (1973), S. 361-373 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus Toxin ; Iodine Labelling ; Spinal Cord ; Autoradiography ; Antitoxin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The in vivo interaction of 125I-labelled toxin with substructures of rat spinal cord has been studied. The rats were poisoned by i.v. injection about 40–50 h before sacrifice. 1. The labelled material accumulates in the grey substance, which is, on microdissection, about 6 times more active than the white. Autoradiography reveals that the toxin is particularly enriched in the ventrolateral part of the grey substance. 2. On ultracentrifugation of the homogenates, the label is preferentially fixed to the dense fractions known to contain the synaptosomes. However, a considerable part of the toxin is fixed to the lighter fractions too. 3. Upon gel filtration, the labelled material in SDS-homogenates from spinal cords poisoned in vivo is indistinguishable from toxin added to the homogenates already prepared. The same is true for the bulk of radioactivity when subjected to disc gel electrophoresis. 4. The labelled material is degraded by enzymes from spinal cord at pH 3.5, but not at pH 7.5. 5. The labelled material is relatively firmly bound to structures of spinal cord. The bonding is fairly resistant against washing, even in the presence of an excess of cold toxin, but it can be partially released by treatment with antitoxin. According to these findings, the labelled material is firmly but not irreversibly bound in vivo to discrete structures, corresponding preferentially to the synaptosomal fractions in the homogenates and the ventrolateral grey in the slices. No evidence has been found for its degradation in vivo. So far, the bulk of labelled material in the spinal cord is indistinguishable from tetanus toxin.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 273 (1972), S. 313-330 
    ISSN: 1432-1912
    Schlagwort(e): Snake Venom ; Phospholipase A ; Potentiation ; Iodine Labelling ; Pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to obtain better insight into the potentiation of the toxicity of phospholipase A by crotapotin, we studied the distribution and elimination of these substances and of their combination. Blood Plasma Concentration. Iodine-labelled phospholipase A leaves the bloodstream of mice and rabbits very quickly after i.v. application. Simultaneous injection of crotapotin speeds the elimination of the enzyme. After subcutaneous application in mice the plasma concentration of phospholipase A depends on the quantity of enzyme injected. It is higher when the enzyme is complexed with crotapotin before injection. The plasma concentration of phospholipase A fails, however, to be proportional to the toxicity of the complex after subcutaneous application. Crotapotin leaves the blood of mice also very quickly after i.v. application. Organ Distribution. After i.v. application in mice, phospholipase A is heavily enriched in the liver. By simultaneous application of crotapotin, the enzyme is partially diverted to the kidneys. Only a small percentage of injected enzyme is found in the brain. This percentage is just significantly raised by simultaneous application of crotapotin. The diaphragm contains about the twofold amount of phospholipase A per wet weight as compared with other samples of skeletal musculature. With crotapotin, there is a slight increase of the radioactivity in all muscles investigated, with different degrees of significance. Crotapotin is enriched in mouse kidneys after i.v. application. Renal Elimination. The renal elimination of the acidic crotapotin is higher than that of the basic phospholipase A. In this respect, the latter resembles the basic polypeptide Trasylol®. Doses of phospholipase A above 0.25 mg/kg cause intravital hemolysis. The hemolysis is prevented if a small amount of crotapotin is applied simultaneously. Our findings show that the combination with crotapotin distinctly alters the pharmacokinetic behaviour of Crotalus terrificus phospholipase A. However, our data do not explain the tremendous increase of phospholipase A toxicity caused by the non-toxic crotapotin.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 290 (1975), S. 329-333 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus Toxin ; Iodine Labelling ; Neurones ; Tissue Culture ; Autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Primary cultures derived from embryonic mouse brain and spinal cord were exposed to 125I-labelled tetanus toxin and subjected to autoradiography. Cells with neuronal, but not glial, morphology selectively accumulated the toxin. The distribution of the grains over these cells and their processes was not uniform, discrete processes showing heavier labelling.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 299 (1977), S. 187-196 
    ISSN: 1432-1912
    Schlagwort(e): Tetanus ; Iodine labeling ; Spinal cord ; Metabolism ; Pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Local tetanus was elicited in rats and cats by intramuscular injection of 125I-tetanus toxin. After different times spinal radioactivity was extracted with either non-ionic (Lubrol PX) or ionic (sodium dodecyl sulfate, SDS) detergents and compared with native or 125I-toxin by gel filtration, SDS-gel electrophoresis, immunological procedures, and toxicity tests. In double-isotope experiments, 131I-toxin was added to the extracts as standard. In rats, the bulk of extracted material was indistinguishable from native toxin. However, there was a slight shift of the extracted material towards smaller molecular weights in gel filtration with Lubrol. In gel filtration with SDS, the toxin peak was followed by some tailing of 125I radioactivity. Accordingly a small part of extracted radioactivity moves faster than the standard in SDS disc gel electrophoresis. These findings taken together indicate some degradation in vivo. Adsorption to solid-phase antibodies indicated that more than 80% of the radioactivity extracted from rats was still immunoreactive. It yielded a zone confluent with extrinsic toxin in immunodiffusion. The spinal cord Lubrol extract from rats was still toxic in the expected range. Due to the very small amounts of toxin present, no precise toxicity data could be given. In cats, there was also some evidence for radioactive split products in both SDS gel filtration and disc gel electrophoresis. The patterns closely resembled those obtained with extracts from rat spinal cord. SDS extracts from rat and cat spinal cords, poisoned with 125I tetanus toxin in vivo, were also subjected to SDS disc gel electrophoresis followign reduction with dithioerythritol (DTE). They yielded large and small chains of the same size as did native toxin. In vitro, extensive degradation with brain homogenate from rats took place at pH 3.65, but not at pH 7.5. This indicates that lysosomal degradation is not a major metabolic pathway of tetanus toxin in vivo, although it is possible in principle. It is concluded that a) unlike other toxins, tetanus toxin is not necessarily degraded during its cellular uptake, b) the bulk of radioactive material is indistinguishable, following its neuronal ascent, from native or labeled toxin, c) a part of the radioactivity is recovered as split products.
    Materialart: Digitale Medien
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