Zur zellulären Aminosäure-Inkorporation im in- und exkretorischen Pankreas unter experimentellen Bedingungen

Summary After glucagon and tolbutamide administration, the protein synthesis in the nucleus increases, especially in the B- but to a lesser extent also in the A-cells. Similar effects are noted in the cytoplasma of B-cells. Already 2 h following alloxan premedication, there is no activity in the nucleus and cytoplasm of B-cells, whereas in the A-cells they are markedly labelled.     

Zur Entwicklung der Gefässe im Herzmuskel

Summary In the developing rat heart 3 periods may be distinguished with regard to the nutrition of the myocardium: (1) Nutrition by diffusion (up to the 12th embryonic day). (2) Period of venous circulation in which the blood passes from the ventricles through sinusoids, capillaries and veins to the coronary sinus. (3) The coronary circulation, which starts with the formation of coronary arteries. By the end of the first week of life, the cardiac circulating system is fully developed.     

Zur Frage des Vorkommens von N-Nitroso-Verbindungen im Tabakrauch

Summary Important facts in connection with the occurrence of N-Nitroso compounds in tobacco smoke have been summarized. This paper reports on analytical methods for the identification of N-Nitroso compounds. The figures known about nitrate content and volatile bases of tobacco, as well as the nitrogen oxides and volatile bases of tobacco smoke as precursors of N-Nitroso compounds, are summarized. The third order reaction of secondary amines with an equimolar mixture of nitric oxide and nitrogen dioxide is a precondition for the formation of N-Nitroso compounds in tobacco smoke. While examining tobacco smoke for N-Nitroso compounds, temperature and time conditions have to be adapted to the natural smoking process. The use of solvent as well as cold traps has to be avoided to exclude the formation of artifacts. Analyses completed under these conditions furnished results of 0.004µg of a mixture consisting of N-Nitroso-dimethylamine and N-Nitroso-pyrrolidine, calculated as N-NO per cigarette. A number of animalexperimental preconditions are still lacking, to judge the biological effects of these extraordinarily small amounts of N-Nitroso compounds.     

Zur Blutdruckwirkung von Aludrin und Adrenalin

Summary The depressor action of small doses of adrenaline on the blood pressure (B.P.) of the decapitated cat may be abolished by pretreatment with pilocarpine; atropine restores the original depressor action. The fall in B.P. due to adrenaline after ergotamine once more becomes an increase when pilocarpine has been given earlier. After atropine a fall in B.P. again occurs. This effect of pilocarpine and atropine on a depressor response has already been described in the case of Aludrine (N-isopropyl-noradrenaline) byFromherz.     

Zur Biosynthese von Reserpinin und Vincamedin

Summary The biosynthesis of reserpinine (II) and vincamedine (IVa) in Vinca plants has been investigated with the help of labelled precursors. Incorporation of 1-¹⁴C-Sodium acetate into the non-tryptophan C₁₀-moiety of these alkaloids occurred only with extensive randomization of the label. In addition, indications were obtained that the methyl group of methionin is not involved in the formation of this fragment.     

Zur Biosynthese des Verbenalins und Aucubins

Summary Verbena officinalis specifically incorporates 2-¹⁴C labelled mevalonic acid in the formation of the aglycone moiety of verbenalin (2). In aucubin (6), isolated fromVerbascum thapsus, the incorporation rate is very low and the main part of the activity is located in the sugar moiety.     

Zur Konstitution des Resibufogenins und Artebufogenins

Summary The structure of Resibufogenin is unambiguously shown to be 3-hydroxy-14, 15-oxido-bufadien-(20, 22)-olide on the basis of new degradation work. Artebufogenin A and Artebufogenin B are 3-hydroxy-14-15-keto-bufadien-(20, 22)-olide and 3-Hydroxy-14-14-keto-bufadien-(20, 22)-olide, respectively.     

Zur Bindung von Biliverdin an das Protein im Crenilabrus-Blau

Summary The blue biliprotein from the fins of the Mediterranean fishCrenilabrus pavo C.V. was analysed with respect to linkages between colouring matter (biliverdin IX) and apoprotein. It was shown by chromic oxidation under various conditions and determination of degradation products that one of the outer and one of the inner rings of biliverdin are free. The remaining inner ring is bound to the apoprotein presumably by an ester bond, while the lability of the linkage between one outer ring and apoprotein corresponds to a N-acyl-bond.     

Fibrinolyse im Kammerwasser menschlicher und tierischer Augen

Summary In the aqueous humour of human subjects and of various animals species, a fibrinolytic system has been demonstrated which, as regards streptokinase, shows the same properties as the corresponding plasma. Presumably the actual fibrinolytic activity in the aqueous humour is greater than in the plasma.     

Zur Kenntnis von Levorin A und Candicidin

Summary A sample of Russian provenance of the antifungal antibiotic levorin A, containing 30,000 microbiological units of activity/mg, was shown to consist of several components. Three components, designated levorin A₁, A₂ and A₃, were isolated and shown to be distinguishable by their partition coefficients in the system chloroform-methanol-borate buffer pH 8.4 (2:2:1). An enriched sample of the antifungal antibiotic candicidin, prepared from a commercial preparation of American provenance, showed a very similar pattern of distribution as levorin A did in 600 transfers. Levorin A₂, the main component of the levorin A sample, was not distinguishable within the error limits of the applied tests, from the main component of the enriched candicidin sample.

---

---

64. Mitteilung der Reihe «Stoffwechselprodukte von Mikroorganismen». 63. Mitteilung: Experientia, im Druck (1968).     

Adrenalin- und Noradrenalinbestimmungen im Blutplasma unter der Geburt

Summary The % adrenaline from the total catecholamines in blood plasma of women under prolonged labor is higher than in plasma of women under normal labor or in healthy adults.     

Tryptophan im aktiven Zentrum von Trypsin und Chymotrypsin

Summary Acid hydrolysis of trypsin and chymotrypsin inhibited by DIP yields seryl-phosphate within a sequence representing one part of the active center. Now it is demonstrated by UV-spectrophotometry that DIP is bound primarily to tryptophane and remains there after peptic degradation. A tetrapeptide containing both tryptophane and phosphate was isolated and analyzed.     

Mineralhaushalt und hormonale Aktivität im Winterschlaf

Summary A review is presented on the metabolism of sodium, potassium, calcium and magnesium during natural hibernation in mammals, and its relation to endocrine activity. With the entrance into hibernation, a change of homeostasis and an initial vagoinsular stage occur, resulting for instance in a hyperpotassemia. When the body temperature falls further, a sympathicoadrenal stage is observed whilst the serum potassium attains its normal level, probably favoured by simultaneous activation of the zona glomerulosa. Most animals show an increase of serum calcium and magnesium in hibernation in consequence of anhydremia, as well as of probably parathyreoid activity. It is suggested that an aldosterone and/or ADH secretion is provoked by diminishing of the intravasal space in deep hibernation. The mineral metabolism of bats differs in several points from that of other hibernators.     

Zur polarographischen Untersuchung von Peroxiden und oxydierten Fetten

Summary The origin of the polarographic peak between 0 and –0.2 V caused by oxidized fats and by different peroxides, especially diacyl peroxides dissolved in LiCl in methanol/benzene, has been investigated with a cathode ray polarograph. This peak is caused by a reduction of Hg-ions. Certain peroxides favour the oxidation of the Hg-metal of the electrode to Hg-ions; thereby the diffusion current is proportional to the peroxide concentration. An addition of Hg-ions to the peroxide solution increases the peak height. Hg²⁺- and Hg⁺-solutions without peroxide yield a similar peak.     

Zur Vorgeschichte und Entwicklung des Krümmungsbegriffs

Ohne Zusammenfassung Vorgelegt von B. L. van der Waerden Martin Barner zum 60. Geburtstag gewidmet     

Zur Umwandlung von β-Pyridylcarbinol in Nicotinsäure im tierischen Organismus

Summary By way of the perfusion technique, it is shown that the liver of the rat readily converts-pyridyl-carbinol to nicotinic acid. The turnover attains a rate of 0.5M/g/min.     

Zur Kristallstruktur der Mineralien der Chabasit- und der Faujasitgruppe

Summary Preliminary results are given on the structure of faujasite and gmelinite.     

Über die Ätiologie der Lippen-Kieferspaltformen und Gaumenspalten beim Menschen und im Tierexperiment

Summary Only formhydroxamic acid and its certain derivatives induce in rats cleft-lip and palate (CLP) after treatment during early embryonic developmental phase. Other hydroxamic acids and formamide-derivatives caused different malformations but no CLP. Also unknown in rats in the hereditary CLP. The possible causes of CLP in rats are compared with these in mice and men.