Effects of three synthetic peptides analogous to neurohypophyseal hormones on the excitability of giant neurones ofAchatina fulica Férussac

Summary Deamino-dicarba-(d-d-)oxytocin andd-d-Arg-vasotocin at 10^–4 kg/l showed an excitatory effect on the periodically oxcillating neurone (PON) ofAchatina fulica Férussac.d-d-Arg-vasopressin had no effect.     

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.     

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.     

Über die Gestalt von Fadenmolekülen in Lösung

Summary Some arguments put forward byG. Bier in a recent article in order to supportH. Staudinger's assumption that chain molecules in solution should behave like straight rigid rods are examined. It is shown that the assumptions made byG. Bier are largely arbitrary. The main argument is the assumption that the C-C-bond in long chain molecules should not show any rotation. As far as this point is concerned, attention is drawn to some recent publications showing that the viscosity of shape of chain molecules can be determined by experiment (specific viscosity and double refraction of flow at high velocity gradients). According to these determinations the time necessary for a complete change of shape, using partially free rotation, is of the order of 10^–5–10^–3 seconds for molecules like nitrocellulose or polystyrene up to degrees of polymerization of several thousands and for viscosities of the solvent of the order of 10^–2 poises.     

Der Mangan- und Kupfergehalt von Chloroplasten und Cytoplasten

Summary Employing catalytic methods, the Mn- and Cu-content was determined in different cell fractions (chloroplasts, cytoplasts) of freeze-dried leaves ofValerianella olitoria isolated with a new dry method byBehrens et al.¹. Cu was found essentially in the fractions with high chloroplast content; Mn was found mainly in the fractions with low chloroplast content.     

Alpha-tocopherol: Its inhibition on human platelet aggregation

Summary Alpha-tocopherol inhibits human platelet aggregation induced by arachidonate sodium, collagen, epinephrine, adenosine diphosphate or thrombin — arachidonate sodium being the most susceptible. The second phase of the biphasic platelet aggregation induced by epinephrine or adenosine diphosphate is preferentially inhibited.This work was supported by the Medical Research Council of Canada, Quebec Medical Council, and a Fraser Scholarship, McGill University. I thank Drs.K. N. Drummond andS. O'Regan for their comments.     

Über die Beziehungen zwischen der Lipidlöslichkeit von Pharmaka und ihrem pharmakokinetischen Verhalten

Summary Some correlations between the physicochemical properties of drugs and their pharmacokinetic behaviour are outlined. Based on the permeability characteristics of simple model membranes (porous membrane, lipid membrane) permeation and distribution of drugs in the animal body can be described and understood on simple physico-chemical terms. Some clinically important aspects — the absorption of drugs from the intestinal tract, the passage through the blood-brain-barrier and the renal excretion as governed by passive tubular reabsorption — are discussed in more detail. Thereby it appears that the solubility of a drug in lipid material, which may be suitably expressed as partition coefficient between an organic solvent and a buffer solution of pH 7.4, is a major factor in determining its pharmacokinetic behaviour.     

Paramyosin-Struktur und Sperrtonus,Untersuchungen am Byssusretraktor vonMytilus edulis mit dem Interferenz-Kontrast-Mikroskop

Summary Surviving muscle fibres of a molluscan smooth muscle (ABRM) in catch exhibit a characteristic pattern of longitudinal stripes when examined with theNomarski technique (Differential interference contrast). The pattern appears to be due to aggregated paramyosin-filaments; it disappears after abolishing the catch with 5-hydroxytryptamine or — in freeze-dried preparation — after raising the pH of the ATP-salt solution.     

Einfluss von Streptomycin und von Tetracyclinen auf die Entwicklung keimender Samen

Summary Euler (1947) andM. L. Stein (1953) had observed that germinating seeds of barley, rye, wheat and other grasses are colourless when exposed to solutions containing more than 0.2% of streptomycin or dihydrostreptomycin. These plants are not inhibited in growth. The chlorophyll already formed is not destroyed by streptomycin.The present authors describe the bleaching effect on germinating seeds of chlortetracycline and tetracycline. These antibiotics inhibit or reduce the formation of chlorophyll in germinating seeds but the authors could not obtain this inhibition without toxic effects (reduced growth). Contrary to streptomycin, the tetracyclines are not able to precipitate nucleic acids and nucleoproteins.     

Der Einfluss von Colchizin und Ethidium-Bromid auf den Gehalt radioaktiv markierter Uridin-Verbindungen in optischen Axonen von Teleosteern

Summary After application of colchicine to one eye, and subsequent injections of³H-histidine or³H-uridine into both eyes, a blockage of the transport in the optic system of teleosts could be demonstrated only for the fast protein-components. However, colchicine is able to depress the effectivity of ethidium-bromide, a blocker of mitochondrial RNA-synthesis. This finding is discussed in connection with the possibility that axonal mitochondria are associated with the neurotubules.

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Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft, die Herrn Prof. Dr.H. Rahmann (Münster) die Mittel zu dieser Untersuchung zur Verfügung stellte.     

Kinetik der hepatischen Farbstoffaufnahme von Indocyaningrün. Einfluss von Bilirubin und Natriumglykocholat

Summary Kinetics of hepatic uptake of indocyanine green, a dye which is used for evaluation of liver function, were studied in the rat. The results indicate that the relationship between ICG-dose and initial hepatic dye uptake obeys Michaelis-Menten kinetics suggesting an interaction of the dye with a carrier or fixed site in the liver cell. Thus it was possible to calculate maximum ICG-uptake (v _max ) and the Michaelis constant (K _m ) of this transport system from several submaximal values.v _max was 7.65 (6-06-9.65)²² mg per 100 g liver/min and K _m 0.56 (0.31–0.81)²². Under the influence of substances which inhibit the elimination of dyes by the liver the parametersv _max and K _m showed changes which allowed characterization of the type of inhibition. While sodium glycocholate had no influence on maximum hepatic ICG-uptake and the Michaelis constant bilirubin caused a significant increase of K _m to 1.29 (0.68–1.90)²² without significantly changingv _max . These data suggest that bilirubin interferes with hepatic uptake of indocyanine green by competitive inhibition and that uptake of bile acids is dependent on a different mechanism.     

Genetische und biochemische Untersuchungen über die Bedeutung der Amino- und Nucleinsäuren im Ursachengefüge von Neoplasmen (Tumoren und Gallen). Ein Dauermodifikationsbzw. Prädeterminationsphänomen

Summary If certain hybrids ofPlatypoecilus maculatus andXiphophorus helleri (viviparous platyfish and swordtails) are cultivated in diluted sea-water (0.25 or 0.5% salt concentration), the amount of free amino acids increases and the growth of macromelanophores, which normally only form certain black spots at the dorsal fin, is accelerated. Therefore melanomas arise. After changing salt water for fresh water, growth of macromelanophores remains accelerated. The same effect is seen in progenies which have been in an oocytic or embryonic state, when their mother was cultivated for some weeks in diluted sea-water (Figures 1 and 2). A similar effect has been observed in plant galls produced byPhylloxera (Viteus vitifolii) in the genusVitis. When the parasite, which injects amino acids into the tissue of the host in order to produce galls, is removed, gall formation goes on slowly for some days. It is shown that a few hours after injection of amino acids—before formation of neoplasms begins—the concentration of ribonucleic acids is increased. RNS-(and therefore protein-)biosynthesis in neoplasms may be dependent on concentration of free amino acids. A simple concept for the formation of neoplasms in hybrids of platyfish and galls ofPhylloxera is discussed.

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Den Herren Prof. Dr.G. de Lattin (Zoologisches Institut der Universität des Saarlandes) und Prof. Dr.B. Husfeld (Forschungsinstitut für Rebenzüchtung Geilweilerhof/Pfalz) sind wir für die Förderung dieser Arbeit zu grösstem Dank verpflichtet. Herrn Prof. Dr.C. Kosswig (Zoologisches Institut der Universität Hamburg) verdanken wir viele Anregungen und die freundliche Überlassung von ingezüchteten Stämmen für unsere Fischkreuzungen. — Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Einige neue Trennungsmethoden und ihre Anwendung auf biochemische und organisch-chemische Probleme

Summary A survey is given of some recent progress, particularly in the author's own laboratory, of methods for the separation of macromolecules and particles of biological origin, as viruses, bacteriophage, microsomes, cell fragments, bacteria and whole cells. Special attention is given to recent developments in zone electrophoresis, protein chromatography, gel filtration and the new partition methods for separation of particles and macromolecules (Albertsson). A number of examples are given to illustrate the various applications. Special emphasis is laid upon the new possibilities for biochemical-genetic studies by application of high-resolution separation methods, and the significance of particle separation methods as applied to fragments of biological structures in providing a tool for structure investigations on a macromolecular level—a field which also should be of considerable interest from a chemical point of view.

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DrittePaul-Karrer-Vorlesung gehalten an der Universität Zürich am 5. Juli 1961.     

High and low affinity transport ofL-arginine in rat brain synaptosomes

The uptake ofL-arginine into purified rat brain synaptosomes was investigated with respect to time and various concentrations ofL-[³H] arginine. Specific uptake was found to be linear with time for up to 5 min of incubation at 37°C. Electrolytes, including sodium chloride, potassium chloride, magnesium chloride and calcium chloride, inhibited uptake of 3 ML-arginine, and the inhibitory effect increased with increased electrolyte concentration under constant osmolarity. It was found thatL-arginine was transported into synaptosomes by two uptake components — a high affinity component (3.5 M) and a low affinity component (100 M). These two components were similar to the Ly⁺ system because of their extreme sensitivity to inhibition byL-lysine andL-ornithine but were distinguishable from each other by kinetic analysis of the uptake data and by their relative sensitivity to inhibition by several amino acids.     

Zur Pathogenese des Urämiesyndroms1. Über den Einfluss von Tyramin auf die Acetoinsynthese aus Brenztraubensäure in Rattenleberhomogenat2

Summary Tyramine enhanced the production of acetoin from pyruvate in rat liver homogenates. A stimulation of acetoin synthesis was only observed, when tyramine was oxidized during the incubation. Tyrosol (p-hydroxyphenylethanol) stimulated acetoin synthesis whereasp-hydroxyphenylacetic acid and ammonia were ineffective.

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Mit Unterstützung des »Schweizerischen Nationalfonds» und der Firma F. Hoffmann-La Roche & Co. AG, Basel.

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8. Mitteilung. 1. Mitt.:H. Thölen, F. Bigler undH. Staub, Path. Microbiol. (Basel)24, 262 (1961). — 2. Mitt.:F. Bigler, H. Thölen undH. Staub, Helv. physiol. Acta19, C 11 (1961). — 3. Mitt.:H. Thölen, F. Bigler undH. Staub, Exper.17, 359 (1961). — 4. Mitt.:F. Bigler, H. Thölen undH. Staub, Schweiz. med. Wschr.91, 1259 (1961). — 5. Mitt.:H. Thölen, F. Bigler, A. Heusler, W. Stauffacher undH. Staub, Exper.18, 454 (1962). — 6. Mitt.:F. Bigler, H. Thölen undH. Staub, Schweiz. med. Wschr.92, 746 (1962). — 7. Mitt.:F. Bigler, H. Thölen undH. Staub, in Vorbereitung.     

Untersuchungen über den Wirkungsmechanismus von Procarbazin (Natulan®)

Summary The cytotoxic methylhydrazine derivative procarbazine or Natulan® has a marked influence on the synthesis of deoxyribonucleic acid in Ehrlich ascites carcinoma cells. The incorporation of³H-thymidine into DNA — measured by autoradiographic methods — is inhibited.     

The photosynthetic energy conversion process in isolated chloroplasts

Zusammenfassung Dieser kurze Überblick über das Gebiet der Photosynthese in isolierten Chloroplasten wäre unvollständig, würde nicht die Abhängigkeit des erzielten Fortschrittes von mindestens zwei «verbesserten analytischen Methoden» betont, welcheEmil Fischers ¹ 60 Jahre zurückliegende Prophezeiung erfüllen. Zur Entdeckung der Photophosphorylierung und der Kohlenhydratsynthese durch isolierte Chloroplasten war die Einführung der Isotopen-Technik in die Biologie durchvon Hevesy ¹⁰⁷ und die Entwicklung der Papierchromatographie durchMartin undSynge ¹⁰⁸ von besonderer Bedeutung.Untersuchungen an isolierten Chloroplasten führten zu einer Auffassung der Photosynthese, die sich von der herkömmlichen Ansicht — als eines CO₂-Assimilationsprozesses — unterscheidet: Die Photosynthese scheint im wesentlichen ein Prozess zur Umwandlung der Strahlungsenergie des Sonnenlichtes in chemische Energie zu sein. Diese Umwandlung steht in engerer Beziehung zur Phosphorassimilation und zur Reduktion des Eisenproteids Ferredoxin als zur Kohlensäureassimilation. Die ersten, chemisch definierten Produkte dieser Energieumwandlungsreaktion in der Photosynthese erwiesen sich nicht als Zwischenprodukte der Kohlenstoffassimilation, sondern als ATP und reduziertes Ferredoxin.

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Based, in part, on a paper presented at the Advanced Study Institute on the Biochemistry of the Chloroplasts, Aberystwyth, Wales, U.K., August 26, 1965. — The research work from the author's laboratory reported herein has been aided by grants from the National Institutes of Health, Office of Naval Research and the Charles F. Kettering Foundation.     

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.     

Zur Pathogenese des Urämiesyndroms. Brenztraubensäure,Acetoin und 2,3-Butylenglykol in Blut von Patienten mit Nieren- und Leberkrankheiten

Summary Acetoin and 2, 3-butylene glycol in blood of renal and hepatic patients are raised, when consciousness is disturbed. There is no correlation between blood levels of acetoin and 2, 3-butylene glycol and the degree of impairment of consciousness. Simultaneous determinations of acetoin and 2, 3-butylene glycol in blood and cerebrospinal fluid show that alterations of the cerebral pyruvic acid metabolism are difficult to detect in circulating blood.

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Mit Unterstützung des «Schweizerischen Nationalfonds» und der Firma F. Hoffmann-La Roche & Co., AG, Basel.

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5. Mitteilung. — 1. Mitt.:H. Thölen, F. Bigler undH. Staub, Path. Microbiol.24, 262 (1961). — 2. Mitt.:F. Bigler, H. Thölen undH. Staub, Helv. physiol. Acta19, C11 (1961). — 3. Mitt.:H. Thölen, F. Bigler undH. Staub, Exper.17, 359 (1961). — 4. Mitt.:F. Bigler, H. Thölen undH. Staub, Schweiz. med. Wschr.91, 1259 (1961).     

Effect of vasopressin on hepatocytic and ductal bile formation in the dog

Zusammenfassung In Studien an 8 cholecystektomierten, mit einerThomas-Kanüle versehenen, nicht-anaesthesierten Hunden konnte nach i.v. Injektion von 0,5 E pro kg Körpergewicht Lysin-8-Vasopressin eine Erhöhung des Gallenflusses um durchschnittlich 55% beobachtet werden. Da die biliäre Clearance von¹⁴C-Erythritol — ein Mass des canaliculären Gallenflusses — gleichzeitig anstieg, die Cholerese aber als Zusatz einer HCO₃ —und Cl^– reichen Flüssigkeit imponierte, scheint es wahrscheinlich, dass Vasopressin hepatocytäre und ductuläre Mechanismen der Gallenbildung beeinflusst.