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1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
Summary The disappearance of thrombin—formed in the blood, or added to serum-follows a manomolecular reaction-type. Heparin increases the reaction-velocity of this thrombin-inactivating process.Our investigation established that toluidine blue or kinase, which, according to the literature, bind heparin, strongly reduce the speed of thrombin-inactivation too. Therefore the heparin-binding capacity of these substances is also manifested in the decrease of thrombin-inactivation.  相似文献   

8.
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.  相似文献   

9.
Summary A single injection of harmaline increases the noradrenaline and adrenaline concentration in the rat heart. The maximum effect is obtained after about 40 min.  相似文献   

10.
Summary Experiments on rats revealed that liver damage caused by allyl alcohol (measured by the rate of necrosis) is enhanced by alcoholic beverages such as ethanol and European or hybride wine. In this respect, wine seems to cause more damage than mere alcohol.  相似文献   

11.
Summary Certain derivatives ofp-benzoquinone and the naphthoquinones cause a strong inhibition of the growth of yeast. The strongest concentrations of some of these compounds even show a fungicidal potency. The authors discuss the possible mode of action of this inhibition.  相似文献   

12.
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.  相似文献   

13.
Summary Embryonic chick bones were cultured in vitro in the presence of progesterone and of a series of progesterone metabolites. It was found that only 5-pregnane-3,20-dione, 3-hydroxy-5-pregnane-20-one, and 4-pregnene-20-ol-3-one influence the growth of bones in vitro in a manner similar to progesterone. All other investigated progesterone metabolites exert either a different or no demonstrable action on bone growth.  相似文献   

14.
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.  相似文献   

15.
Summary The growth ofBacterium coli commune in culture-medium afterFriedlein containing glucose was controled by photometry. Addition of uracil hastens the growth slightly, addition of adenin delays it. The curve of growth with adenin shows two maxima similarly as the primary and secundary effect after irradiation of biological material by ultrashort rays. As known the irradiation of nucleic-acids sets in partial freedom purins and pyrimidins. These are changed again by intense irradiation. The news products of irradiation have probably also biological influences.  相似文献   

16.
Summary Previous experiments indicating antagonistic effects of cardiac glycosides and corticosteroids on ion transport in red cells and published independently from our own laboratories1 and byBernstein 2 could not be repeated under a variety of experimental conditions.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
Summary The macrotetralid antibiotic Dinactin uncouples phosphorylation from electron transport in illuminated chloroplasts in the presence of Na+ at lower concentrations than in K+, while the light-induced proton uptake is more inhibited in a medium with K+ than with Na+. The large volume changes of whole chloroplasts in the light and after addition of Dinactin are parallel to the amount of K+ in the chloroplasts.

Die Resultate der vorliegenden Arbeit entstanden zusammen mitElisabeth Bosshard-Heer, H. R. Hohl, Ch. Pflugshaupt undIngrid Specht-Jürgensen. Wir danken dem Schweizerischen Nationalfonds für die grosszügige Unterstützung.  相似文献   

20.
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.  相似文献   

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