Der Einfluss von Acetylcholin auf den Calciumumsatz ruhender und kontrahierender Vorhofmuskulaturin vitro

Summary Acetylcholine 5 × 10^–8 g/ml reduces the Ca⁴⁵ uptake of the beating left atria of guinea-pig; the tissue calcium is not altered. In resting atria, acetylcholine 5 × 10^–7 g/ml has no influence upon the calcium content and Ca⁴⁵ uptake. It is concluded that acetylcholine acts by shortening the action potential duration and thereby reduces the release of cellular calcium per excitation.

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Mit grosszügiger Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Elektrolytgehalt von Endo- und Perilymphe in den einzelnen Schneckenwindungen des Meerschweinchens ohne und mit Stimulation

Summary A freezing method is described which permits the measurement of electrolytes and enzymes in the peri- and endolymph from a single turn of the cochlea of guinea pig at a known time. The perilymphs of the scala vestibuli and the scala tympani are different, especially in the first basic turn. This difference may be produced by a partial semipermeability of the Reissner's membrane. After producing deafness by a sound of frequency 2000 c/s, the potassium (the total potassium level detected chemically and by the use of potassium-42) increases in the perilymph of the second turn only, and decreases slightly in the endolymph of the same turn. In the other turns, the potassium does not change.This method permits the analysis of chemical changes due to the stimulus of single sounds.

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Die Arbeiten wurden mit Unterstützung des Schweizerischen Nationalen Forschungsfonds durchgeführt.

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Technische Hilfe leisteten uns in dankenswerter Weise Dr.R. A. Collet, Isotopenlabor, Zentrallaboratorium des Kantonsspitals, und. Dr.Fischer (Kältekammer von – 15°C), Centre de transfusion, Kantonsspital Genf.     

Neuronenaktivität hypothalamischer Kerngebiete von Kaninchen nach intraventrikulärer Applikation von Vasopressin und Oxytocin

Summary Intraventricularly applied vasopressin ncreased, and oxytocin decreased, the impulse activity of neurones in the paraventricular and supraoptic nuclei. We found a shorter reaction time for the paraventricular nucleus in comparison with the supraoptic nucleus.

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Diese Arbeit wurde mit Mitteln des Ministeriums für Wissenschaft und Technik der DDR durchgeführt.

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Die Autoren danken FrauE. Müller und Frl.H. Papajewski für gewissenhafte technische Assistenz.     

Absorptionsspektrum von Melaninpigment

Summary The microphotometric absorptiometry of single isolated melanin granula and the photometric analysis of a KOH extract from a melanoblastoma metastasis show an extinction strongly increasing to the violet end of the spectrum, without any remarkable extinction maximum.

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Die Arbeit wurde mit Unterstützung der Deutschen Forschungsgemeinschaft ausgeführt.     

Ultramikromethoden. Darstellung von Diazomethan; Methylierung von Fettsäuren mittlerer Kettenlänge

Summary A device for the small-scale generation of diazomethane is described, as well as the methylation by this reagent of nanogram amounts of the following fatty acids: butyric, caproic, caprylic, capric, lauric.

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3. Mitteilung:S. Huwyler, Experientia28, 1393 (1972).

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Herrn Prof. Dr.M. Viscontini danke ich für wertvolle Diskussionen und dem Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung für die finanzielle Unterstützung.     

Verbesserte Methode zur Gewinnung und Verarbeitung von freien Zellen aus kleinsten Volumina von Körperflüssigkeiten mittels Membranfiltration

Summary A cell collector for concentrating small numbers of exfoliated cells on membrane filters from minute volumes (0.05–3 ml) of body fluids and culture media is described. The apparatus incorporates a membrane pump, delivering a vacuum of 10–100 mm Hg. Filtration units (funnels and filter holders) with filtrating areas of 3, 5 and 8 mm diameter are used depending on the volume and the cell content of the fluid to be investigated. A rapid staining procedure based on the classical May-Grünwald-Giemsa technique for light microscopic observations and a modified technique for processing the cell-coated filters for electron microscopy are presented in some detail.

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Mit Unterstützung durch den Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung.     

Zur Struktur von Scotophobin

Summary The biological and chemical properties of one of the synthetic peptides Seryl-asparagil-asparaginylasparaginyl-glutaminyl-glycyl-glycy-lysyl-seryl-alanyl-glutaminyl-glutaminyl-glycyl-glycyl-tyrosylamid are identical with those of the natural scotophobin.

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Wir danken der Robert A. Welch Foundation, Houston, Texas, für die finanzielle Unterstützung dieser Arbeit. Herrn Prof. Dr.G. Ungar, Baylor College of Medicine, Houston, Texas danken wir für die Ausführung der biologischen Tests.     

Die Transformation von Mesothelzellen in Hyaluronsäure produzierende Siegelringzellen

Summary After injection of PHA into the peritoneal cavity of rats, parietal mesothelial cells were transformed into hyaluronic-acid-producing signet-ring-cells.

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Die Untersuchungen wurden mit Unterstützung der Deutschen Forschungsgemeinschaft durchgeführt.     

Die Wirkung von Spirolactonen und von Herzglykosiden auf den Natrium- und Kaliumtransport an Erythrocyten

Summary Experiments made on human red cells showed that spirolactones (SC 5233 and SC 9420) added to the sample as dry powder (10^–3 g/ml) exert an inhibitory action on the active transport of sodium and potassium across the cell membrane. Spirolactone at its saturation concentration in serum (1.5×10^–5 g/ml), however, was ineffective.The inhibitory action was not affected by aldosterone or hydrocortisone.Experiments involving exposure of red cells to spirolactone and a cardiac glycoside simultaneously led to the conclusion that these substances do not have the same mechanism of action. The inhibition caused by spirolactone added to the inhibition due to a supramaximal concentration of ouabain (5 × 10^–4).

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Diese Arbeit wurde unterstützt durch ein Stipendium der CIBA für naturwissenschaftliche, medizinische und technische Forschung.     

Das Na-Transportsystem während der Erregungsprozesse am Ranvier-Knoten isolierter markhaltiger Nervenfasern

Summary (1) An attempt is made to interpret the action potential of medullated nerve fibres of the frog in terms of permeability changes to Na ions.(2) In keeping with a suggestion byHodgkin andHuxley, the following assumptions are made: (a) a carrier system is responsible for transporting Na ions across the nodal membrane; (b) in a resting fibre (high membrane potential) its transport capacity is small; (c) depolarization has a dual effect on the transport system, namely activation of carrier groups as a quick reaction and inactivation of the whole system as a slower reaction.(3) The following experimental observations are interpreted on the ground of these assumptions: threshold for depolarization, threshold for repolarization, absolute and relative refractory period, alteration of the action potential on application of a hypertonic (5%) NaCl solution.

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Eine vorläufige Mitteilung erfolgte auf der Tagung des Schweiz. Vereins für Physiologie usw. in Fribourg 1956. Helv. physiol. Acta14, C35–36 (1956).     

Identifizierung von Substanzen durch Simultan-Chromatographie isotopenmarkierter Verbindungen

Summary Weightless amounts of radioactive test-mixtures are run from the same starting point as the compounds to investigate while checked independently. It is shown that this allows a dependable identification even in cases where the technique of inactive parallel running test-mixtures fails completely.

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Für die finanzielle Unterstützung dieser Arbeiten danken wir dem Bundesministerium für Atomenergie und Wasserwirtschaft.     

Die Wirkung von Theophyllin auf den cellulären Ca-Stoffwechsel des Warmblüterherzens

Summary In isolated, electrically driven, left guineapig atria, theophylline (5×10^–4 g/ml) increased the rate of⁴⁵Ca uptake and release without affecting the total myocardial Ca content and the amount of exchangeable cellular Ca. In sheep and calf heart preparations, theophylline (10^–4–10^–3 g/ml) increased Ca inward current during excitation (as examined indirectly by Ca dependent changes of membrane potential in TTX-containing solutions) as well as tension development. It is concluded that the positive inotropic effect of theophylline in mammalian hearts is due to an increase in Ca influx during the excitation process.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Reinigung von F-antigen

Summary F-antigens are glycoproteins with s ₂₀ ^c , 0.1M NaCl=5.4 and a main component in SDS-polyacrylamide of molecular weight of 40,000. Separation of F-antigens is described; with the methods used they are indistinguishable.

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Arbeit mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung (Kredit Nr. 5254.3). Herrn Dr.H. Mosimann danke ich für die Hilfe bei der analytischen Ultrazentrifugation, Frl.U. Kohler für Mitarbeit und Herstellung der Skizzen.     

Multiple Innervation von Muskelfasern imM. vocalis des Menschen

Summary In contrast to the narrow terminal innervation bands of human skeletal muscles, the vocal muscle shows a particularly extended region of synaptic contacts. A great number of muscle fibres receive two or more motor endings forming individual endplates at a distance of several hundred micra. The physiological significance would be a more rapid activation.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.

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Frl.Ingeborg Schnöring danke ich für wertvolle techn. Hilfe.     

Beziehungen zwischen laccase- und peroxidaseartigen Isoenzymen von Basidiomyceten

Summary Phenoloxidases of 30 wood-rotting fungi were separated by isoelectric focusing. It turned out that apparent peroxidasic activity of the crude extracts of certain species is not necessarily atributable to peroxidases but to the special properties of certain laccase isoenzymes, which may be uninfluenced, inhibited, or activated by H₂O₂. These interactions differ in certain species for intra- and extracellular forms of the same isoenzyme.

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Wir danken den technischen Mitarbeitern unseres Lehrstuhls, besonders FräuleinK. Kuprat, für ihre Unterstützung und der DFG für Sachmittel.     

Experimentelle Untersuchungen zum Wirkungsmechanismus der beiden entwicklungsphysiologisch aktiven Fraktionen des «Gehirnhormons» der Insekten (Aktivationsfaktor I und II) auf die Prothoracaldrüse

Summary 2 prothoracotropical factors (activation factor I and II) have been obtained by gel filtration techniques from brains and corpora cardiaca of the cockroachPeriplaneta americana. In contrast to activation factor II, activation factor I caused significant influence of RNA synthesis. The RNA pattern of prothoracic glands stimulated by activation factor I as demonstrated by polyacrylamide gel electrophoresis consists of different kinds of RNA. Short time incubation revealed effects on sRNA synthesis, while long time incubation demonstrated predominantly increase of ribosomal RNA synthesis. Measurements of the membrane potential of the prothoracic gland cells of the wax mothGalleria mellonella indicated an increase by activation factor II; activation factor I was without any visible effect. Our results demonstrate for the first time that the two activation factors induce different effects at cellular level.

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Für technische Unterstützung danken wir FräuleinA. Zinsser und FrauR. Meissner.

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Durchgeführt mit Mitteln des Ministeriums für Wissenschaft und Technik und mit Unterstützung durch die Sächsische Akademie der Wissenschaften zu Leipzig.     

Nachweis von Scilliglaucosidin in den Zwiebeln vonBowiea volubilis Harvey

Summary Hellebrigenin was converted to Scilliglaucosidin-19-ol and 3-Epi-Scilliglaucosidin-19-ol. This proves the correctness of the assumption ofStoll et al. ³ that the aldehydic group of Scilliglaucosidin is in position C-10.Comparison of a reduction product of Nabogenin, a substance isolated earlier from the bulbs ofBowiea volubilis Harvey, with Scilliglaucosidin-19-ol and 3-Epi-Scilliglaucosidin-19-ol showed its identity with the first named compound. This proves that the so called Nabogenin was a mixture consisting mainly of Scilliglaucosidin.

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8. Mitteilung über die Glykoside vonBowiea vocubilis Harvey und 162. Mitteilung über Glykoside und Aglykone.

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7. Mitt.:A. Katz, Helv. chim. Acta38, 1565 (1955).

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161. Mitt.:H. Kündig-Hegedüs undO. Schindler, Helv. chim. Acta39, 904 (1956).     

Retinalfalten im auge von wassersäugetieren

Summary The folds found in the retina of 3 orders of mammals, the white whale, the hippopotamus and the otter, are described. All the layers of the retina take part in the folds, with the exception of the pigmented epithelium. The folds are a morphological adaptation to aquatic life.

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Durchgeführt mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung (Gesuch Nr. 3883).     

Der Einfluss von Calcium auf die Brenzcatechinaminfreisetzung

Summary (1) Experiments on isolated perfused suprarenals of cattle have shown that the acetylcholine-induced release of catechol amines, but not that of phenylethylamine, is dependent on calcium, since a perfusion with calcium-free Tyrode's solution abolishes the action of acetylcholine and not that of phenylethylamine. (2) Inincubation experiments with isolated chromaffin granules, calcium produces a dose-dependent, significant release of catechol amines even in physiological concentrations (2.5 mM). (3) Acetylcholine does not release catechol amines from isolated granules, either in the presence or in the absence of calcium.

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Forschungs-Stipendiat der A. von Humboldt-Stiftung.

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Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Eine neue Methode zur Darstellung von Desoxyzuckern

Summary A new method for the preparation of desoxy sugars and the elucidation of their structure is described.

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Die ausführliche Publikation erscheint in den Helv. chim. acta.