Der Einfluss verschiedener Psychopharmaka auf den Bluthistamingehalt von Ratten

Summary The concentration of histamine in plasma of rats is changed by injection of psychopharmacons as follows: decreased by narcotics (ether, chloroform) and phantastics (LSD, mescaline), increased by tranquilizers (reserpine, chlorpromazine) a hypnotic (numal) and psychotomimetics (iproniacide, amphetamine).     

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.     

Der Einfluss von adrenergen Rezeptoren-Blockern auf die Wirksamkeit von Strahlenschutzsubstanzen

Summary The effect of -adrenergic receptor-inhibitors was examined in relation to the effectiveness of radioprotective agents. The results, when mice were irradiated, show that the receptor-inhibitors significantly reduced the effect of the applied protectors.     

Der Einfluss von Chlorpromazin auf die oxydative Phosphorylierung von Tumormitochondrien

Summary High concentrations of chlorpromazine cause a considerable decrease of the oxidative phosphorylation of tumor mitochondria and rat liver mitochondria. Regarding preliminary experimental and clinical investigations, we assume that malignant tumors can be sensitised to cytotoxic substances and ionising radiations impairing their energy metabolism by uncoupling the oxidative phosphorylation.     

Der Einfluss von 2-Deoxy-D-glucose auf die Substratoxydation in Ascites-Tumorzellen

Summary The effect of the glycolytic inhibitor 2-deoxy-D-glucose on the oxidation of¹⁴C-labelled substrates of the tricarboxylic acid cycle was investigated in ascites carcinoma cells of the mouse. In the presence of high concentrations of glucose, deoxyglucose stimulates the oxidation of pyruvate C-2 and C-3 to CO₂, but not the oxidation of succinate C-1,4 to CO₂. While deoxyglucose causes, in the absence of glucose, an inhibition of the oxidation of exogenous palmitate C-1 to CO₂, it causes, in the presence of glucose, a stimulation of the palmitate oxidation. There is a possible correlation between the effect of deoxyglucose on the intracellular ATP metabolism and the effect of deoxyglucose on the palmitate oxidation.     

Der Einfluss des Urin-pH auf die Aktivität von Urinenzymen

Summary The relationship between the pH of urine and the measured activity of ULDH, UAP and UAA was investigated in vivo and in vitro. The activity of ULDH and UAP is only half as much, or less, in acid urine (pH 4.8–5.1) as it is in alkaline urine (pH 7.0–8.1). The UAA activity, however, does not change in the pH range measured. The isoenzymes ULDH 2–4, present in alkaline urine of normal adults, does not appear in acid urine.     

Der Einfluss von Tetracyclin auf die Vermehrung des Kartoffel-Blattrollvirus im VektorMyzus persicae

Summary Tetracycline hydrochloride treatment decreased the transmission rate of potato leafroll virus (PLRV) byMyzus persicae. It also prevented the PLRV-induced swellings of the A/F nuclei of the salivary gland. Apparently there is a connection between these two phenomena. The A/F cells may be a site of virus multiplication.     

Der Einfluss von Halothan und Chloroform auf die Feinstruktur und Proteinsynthese der Rattenleber

Summary Examinations by electron microscopic and autoradiographic techniques of whether chloroform and halothane alter protein synthesis in rat liver, demonstrate, that chloroform causes an early destruction of the granular endoplasmatic reticulum accompanied by a marked decrease of the protein synthesis in the centre of the acini. After anaesthesia with halothane, the granular endoplasmatic reticulum and the protein synthesis proved to remain unaffected.     

Der Einfluss von Adrenalin auf das Verhalten des zellulären Kalziums während der K-Depolarisation des Herzmuskels von Meerschweinchen

Summary The effect of adrenaline on the cellular calcium exchange during the K-depolarization of myocardium was studied in isolated left auricles of guinea-pigs by means of the⁴⁵Ca. Increasing the extracellular K-concentration from 2.7–30 mM without corresponding reduction in sodium concentration results in a depression of contraction strength of the myocardium when current is applied. The depression is immediately reversible by using adrenaline. This was associated with a significant increase of the⁴⁵Ca exchange.     

Der Einfluss von Acetylcholin auf die42Kalium-Abgabe postnataler,denervierter und reinnervierter Skeletmuskulatur

Summary The loss of⁴²K from the isolated rat diaphragm into the bathing solution is increased by acetylcholine, (a) 3 to 4 days after birth, (b) 7 to 14 days after sectioning of the phrenic nerve. The⁴²K loss is not altered by acetylcholine in the diaphragm of adult rats and after the denervated diaphragm has become reinnervated.     

Der Einfluss von 4-Benzylhydroxy-3,5-dijodbenzoesäure auf die oxydative Phosphorylierung von Leber- und Tumormitochondrien

Summary The effects of 4-benzylhydroxy-3,5-diiodobenzoic acid on isolated mitochondria ofWalker carcinosarcoma 256 and liver tissue of the same animals were compared. It was shown that, by the same concentrations of the uncoupling halo-phenol, the oxidative phosphorylation of tumor mitochondria was impaired in a higher degree than that of liver mitochondria.     

Der Einfluss der Adenosintriphosphorsäure auf die Strahlenpneumonitis

Summary The administration of adenosintriphosphate in a dosage sufficient to decrease mortality to a significant degree does not decrease the incidence of radiation pneumonitis. Thus, the effect produced by ATP seems to depend on its action upon protein metabolism rather than on morphological cell structures.     

Zum Einfluss von Angiotensin II auf die Nebennierenrinde unter chemischer adrenostase mit SU 4885 (Metopiron)

Summary The inhibition of 11--hydroxylase in the adrenal cortex with SU 4885 (metopiron) increases the ACTH-secretion. Val₅-angiotensin II blocks the reaction of the anterior pituitary gland similarly as does dexamethasone. Mode and intensity of this action of angiotensin II, and the influence on rats treated as described, are studied.     

Der Einfluss der γ-Globuline auf die Viskosität

Summary Depending on concentration of fibrinogen, increasing concentrations of -globulines cause an exponential increase of viscosity, which is more pronounced, the higher the basic concentration of fibrinogenis. Fibrinogen that is dependent on -globulines and albumin, -globulines that is dependent on albumin, or albumin that is dependent on fibrinogen and -globulines do not show this behaviour.

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Für die zuverlässige Mitarbeit sei der biochem.-techn. Assistentin, Fräulein Ilse Stelter, gedankt.     

Das hypoxiebedingte EEG-Arousalstadium unter dem Einfluss von Pentobarbital und Urethan

Summary The influence of pentobarbital and urethan on the hypoxia induced EEG arousal was studied in adult rats and rabbits. A depression of this EEG reaction by pentobarbital was found, while the arousal was unchanged by urethan. A possible mechanism for these findings is discussed.     

Der Einfluss sogenannter Ovulationshemmer auf die Esteraseaktivität des Endometriums

Summary Histochemical investigations were carried out in the endometrium of guinea-pigs after administration of Anovlar (4 mg ethinylnortestosterone-acetate and 0.05 mg ethynylestradiol). Histochemically a decrease of non-specific esterase activity was found in the endometrial as well as in the glandular epithelium after Anovlar treatment. The relationship of this enzyme to synthetic steroid hormones is briefly discussed.     

Der Einfluss der Epiphyse auf die Lokomotionsaktivität bei Ratten

Summary After pinealectomy adult hypoactive rats show an increased exploratory behavior, whereas adult hyperactive rats show no significant behavioral change. These data are discussed in relation to brain serotonin content.

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Durchgeführt im Rahmen des DFG-Schwerpunktprogrammes Neuroendokrinologie (Vo 135/4).

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Frau Dr. D. Freund, Mainz, danke ich für die Erlaubnis zur Benutzung der Open-Field Anlage, Frau H. Untiedt für technische Hilfe bei der Pinealektomie.     

Veränderungen des Glucoseabbaus in Kaninchenaorten unter dem Einfluss von Biguaniden

Summary The influence of biguanides on glucoseoxidation was studied in intima-preparations of rabbit aortae. With high doses (500 µg/ml) an inhibition of CO₂-formation predominantly from position C-1 of glucose was found. With 4 µg/ml there was no significant change of CO₂-for-mation from glucose.     

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.     

Retinale Impulsaktivität und Elektroretinogramm unter dem Einfluss von Desipramin

Summary The influence of Desipramin on ERG and optic nerve activity (42 single neurons) was studied in 8 cats. The drug strongly suppressed the spontaneous activity of the neurons, leaving the response to illumination practically uninfluenced. Thec-wave of the ERG was increased. There is little doubt about a pure retinal origin of the effects.