Wirkung des Chinidins auf die oxydative Phosphorylierung und auf den K-Gehalt in den Mitochondrien des Herzmuskels

Riassunto L'azione della diidrochinidina sulle fosforilazioni ossidative e sul contenuto di potassio nei mitocondri di cuore di coniglio è stata studiata con tecnica manometrica. Si osserva che tale sostanza deprime ma non dissocia la fornitura ossidativa del fosforo inorganico e che determina un aumento del contenuto di potassio nei mitocondri. Tale dato concorda con i risultati degli studi sul meccanismo d'azione della chinidina e suggerisce che questa sostanza provochi una ritenzione di potassio anche nei mitocondri oltre che nella cellula integra.     

Die Wirkung von Herzglykosiden und Kalzium auf den Kaliumtransport im Herzmuskel

Summary In isolated perfused guinea pig hearts, both strophanthin and calcium produced positive inotropic effects and contracture increasing with the concentration of the drugs. Strophanthin caused a net loss of potassium from the heart to the perfusing fluid whereas calcium did not interfer in the same way with potassium exchange. The data are consistent with the view that the positive inotropic effect of cardiac glycosides depends mainly on the increased intracellular calcium concentration, perhaps due to inhibition of the active potassium and sodium transport.     

Die Wirkung von Adrenalin auf den ermüdeten Soleus der Katze

Summary Adrenaline increases the isometric tension of the soleus muscle of the cat when the muscle is brought to fatigue by continuous stimulation at high frequencies. This is in contrast to the effect of the amine upon the nonfatigued soleus muscle.     

Die Wirkung von Na3[Ca-DTPA] auf den Glykogengehalt von Niere und Leber der Ratte

Summary DTPA, a derivative of EDTA, in doses of 1, 2, 4, and 8 mmoles kg^–1/d ^–1 causes a histochemically detectable increase of glycogen in the kidneys and a decrease of glycogen in the liver of rats. Furthermore, a severe damage of the intestinal mucosa has been demonstrated; its possible relevance for the pathogenesis of the other findings is discussed.     

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).

---

---

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

Zur Wirkung von Narkotin auf den Hustenreflex und auf die Bronchialmuskulatur

Summary In experiments on cats cough reflexes were elicited by mechanical stimuli applied to the mucosa of the tracheobronchial tree. Narcotine was found to diminish or to depress the cough reflex in doses of 0.1–1.0 mg/kg and was thus about as effective as codeine. On the bronchial muscles narcotine produced no effect or a bronchodilatation whereas codeine produced a bronchoconstrictor effect. As an isochinoline derivative narcotine should not be liable to cause addiction.     

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.

---

---

Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Die Wirkung der Lipoid- und Polysaccharid-Komponente endotoxischer Lipopolysaccharide gram-negativer Bakterien auf die Leukozytenkultur

Summary Highly purified lipopolysaccharides derived from gramnegative bacteria (endotoxins) stimulate the migration of leucocytes from cultures of chick leucocytes. This effect, as well as many endotoxic manifestations of the preparationsin vivo (pyrogenicity, toxicity, etc.), is induced by their lipid fraction (lipid A), while the respective species-specific polysaccharide functions as lyophilizing carrier which, fundamentally, can be substituted by other inert carriers (e.g. protein).     

Die Wirkung des Hydrocortisons auf die infektionsbedingte lokale Leukozytenansammlung

Summary The aggregation of leucocytes provoked in the peritoneal cavity of the white mouse by intraperitoneal injection of livingE. coli is inhibited by large doses of hydrocortisone. At the same time, the animal's susceptibility to infection is enhanced. The aggregation of leucocytes induced by injection of a bacterial extract containing lipopolysaccharides is inhibited in a similar manner. The effect of hydrocortisone sets in rapidly and subsides within 24 h. The inhibitory effect of hydrocortisone on the lipopolysaccharid effect on leucocytes seems to be an important factor in the influence of hydrocortisone on the infectious process.     

Die Wirkung von Desoxycorticosteron auf den aktiven Kationenaustausch an Rattenblutzellen

Summary Cold-stored blood cells of rats, which were depleted of potassium and had gained an equivalent amount of sodium instead, were incubated with 500 mg% glucose at 37°C in serum. Under these conditions an extrusion of sodium from and a re-entry of potassium into the cells could be observed. Desoxycorticosterone, when added in a concentration of 1 mg per ml, was able to slow down the rate of this exchange to three fifths of the rate of untreated cells. With blood of adrenalectomised rats, the same effect of DOC was observed, although the rate without DOC was somewhat lower than in the blood of normal animals. There was no statistically significant difference between the DOC-effect in blood of normal and adrenalectomised rats.     

Die Wirkung von Benzpyren,Zigarettenrauchkondensat und passiver Berauchung auf die Bildung der Zoxazolaminhydroxylase

Summary Treatment with Benzo(a) pyrene, cigarette smoke condensate and cigarette smoke on hamsters and rats is able to induce zoxazolaminhydroxylase. Enzyme activity in hamsters is a priori higher, whereas the enzyme system in rats is of higher inducibility.     

Die Wirkung von Silymarin-N-methylglucamin-Salz auf den mikrosomalen Gehalt von Cytochrom P450 der Rattenleber bei akuter Thioacetamidintoxikation

Summary 24 h after Thioacetamide application (300 mg/kg body weight) on rats, microsomale Cytochrome P450 content is diminished about 40%. Prophylactic i.p. application of 400 mg Silymarine-N-methylglucamine salt, dissolved in 4% Polyvinylpyrrolidone solution, given 1 h before application of Thioacetamide. counteracts this diminution.     

Die Wirkung von Adrenalin auf das Ruhepotential von Myokardfasern des Vorhofs

Summary Dog auricle fibres were impaled by 2 intracellular electrodes. The first electrode measured the effect of adrenaline on the resting potential, and through the second one electrotonic impulses were applied.Adrenaline increases the resting potential by 1–35 mV. The polarisation is higher at a low resting potential and increases with the dose.Small polarisations were not accompanied by a detectable change of the membrane resistance. During higher polarisations, the membrane resistance was reduced to 50%.

---

---

Ausgeführt mit Unterstützung der deutschen Forschungsgemeinschaft.     

Die Wirkung der Temperatur auf das Verhalten der Gewebsatmung poikilothermer und homoiothermer Tiere unter dem Einfluss von 4,6-Dinitro-o-kresol

Summary (1) The liver respirationin vitro of mice and toads was studied under the influence of 4,6-Dinitro-o-cresol at temperatures varying from 17,5 to 42,5°C.(2) The percentage activity of the oxygen uptake of the mouse liver decreased progressively under dinitrocresol with rising temperatures, whereas the respiration of the toad liver showed inhibition at low temperatures and activation at higher temperature.(3) The results were interpreted following the theory of inhibitory types ofJohnson.     

Die Wirkung von Vasopressin und Oxytocin auf das Nervensystem von Insekten

Summary Vasopressin and oxytocin are antagonistically effective substances with inverse dependence on concentration in the nervous system of insects. These results emphasize the central importance of neurohormonal control of general response in the nervous system.     

Die Wirkung von Persantin auf Herzmuskel-Sarkosomen

Summary Addition of Persantin to respiring beef heart mitochondria leads to a considerable increase of the P/O-ratios in the presence of various substrates. Apparently Persantin is capable of bringing about a tighter coupling of oxidation and phosphorylation.     

Einfluss des Licht-Dunkel-Wechsels auf den O2-Umsatz der Rattenleber

Summary Similar diurnal periodicity in oxygen consumption of liver slices in Wistar rats was observed as that previously found in Sprague-Dawley rats. The rate of oxygen consumption was low in the morning and high in the evening. After inversion of lighting regimes, the phase shifted and reached the reversal curve in about 30 days. On the basis of these findings, it is estimated that diurnal periodicity in oxygen consumption of liver slices is influenced by alteration of the periods of light and darkness. Liver glycogen rhythm showed a reversed correlation to that of oxygen consumption in both lighting regimes.     

Die Wirkung der Askorbinsäure auf die Katalaseinduktion in Mikroorganismenkulturen

Summary Catalase activity ofStaphylococcus aureus increases the effect of ascorbic acid. Namely the ascorbic acid decreases the dissolved oxygen content of the medium, and low oxygen tension is the natural inducer of catalase synthesis.     

Die Pterine in der Haut und in den Augen vonSalamandra salamandra nach Aufzucht auf verschiedenfarbigem Untergrund

Summary Concomitantly with the morphological colour-change, larvae of Salamandra salamandra show a quantitative change in their pteridines. After being reared on a yellow background, all pteridines of the skin (isoxanthopterin and its derivatives, yellow pteridine, photosensitive pteridine) increase by about 1/3 as compared with the animals on a black background. In the retinal pigmentlayer especially, the photosensitive pteridine is augmented.