Bromothricin

Summary Streptomyces antibioticus (Waksman andWoodruff)Waksman andHenrici 1948, strain Tü 99, produced Bromothricin instead of Chlorothricin, when it was grown in a nutrient medium containing 0.5% potassium bromide. The properties of bromothricin are very close to those of chlorothricin. Its nature was elucidated by degradation to methyl 5-bromo-2-methoxy-6-methylbenzoate.     

Änderungen der Entladungsfrequenzen des elektrischen Organs bei verschiedenen Verhaltensweisen eines Nilhechtes (Gnathonemus petersii)

Summary Observing the discharge-frequencies of the electrical organ ofGnathonemus petersii, it was found that there are characteristic frequencies in relation to different behaviour as: slow and fast swimming, at rest, at appetive and agressive behaviour. No such characteristic frequencies could be detected in relation to comfort movements.     

Structure-activity relationship of various acyl derivatives of 6-methyl-8β-aminomethyl-10α-ergoline (dihydrolysergamine)

Riassunto Alcuni acil derivati dell'ergoline hanno dimostrato notevoli proprietà ossitociche, adrenolitiche ed anti-5-idrossitriptaminiche, (anti-5-HT). In particolare l'acetil e l'isobutirril diidrolisergamina possiedono una azione ossitocica altrettanto potente e più elettiva dell'ergometrina, della quale sono anche meno tossiche.     

Die Hemmbarkeit der inhibitorischen Adrenalinbzw. Noradrenalinwirkung durch Adrenolytika

Summary Dibenamine, dihydroergotamine, regitin and priscol were found to antagonize specifically the inhibitory action of adrenaline and noradrenaline on the electrically stimulated isolated ileum of the guinea-pig. The antagonistic action of dibenamine was irreversible.     

Lipoperoxidation rates and drug-oxidizing enzyme activities in the liver and placenta of some mammal species during the perinatal period

Summary Lipoperoxidation and drug-metabolizing enzymes were measured in livers and placentas of different mammal species during the perinatal period. In placentas and fetal livers of rat, rabbit and guinea-pig, cofactor-supported lipoperoxidation was negligible, as were the activities of drug-oxidizing enzymes. Human fetal liver contained an intact drug-oxidizing electron transport chain, and lipoperoxidation activity was accordingly observed. It is suggested that lesions mediated by lipoperoxidation may be possible in human fetus, but they are less probable in animal fetuses.The skillful technical assistance of Ms.Liisa Tuhkanen and Ms.Vuokko Väisänen is gratefully acknowledged.     

Membrane potential of a ranvier node measured after electrical destruction of its membrane

Zusammenfassung Mit Hilfe starker positiver Impulse ist es möglich, durch elektrischen Durchschlag die erregbare Membran eines einzelnen bespülten Ranvier-Knotens vollständig zu zerstören und das Membranpotential zu null zu machen. Auf diese Weise ist es möglich, auch mit Aussenelektroden Anhaltspunkte über die absolute Grösse des Membranpotentials zu erhalten und den Kurzschlussfaktor zu berechnen, falls der Längswiderstand zwischen den Ableitelektroden nicht ohnehin so hoch ist, dass der Kurzschlussfaktor praktisch gleich eins ist und die absoluten Werte direkt gemessen werden können.

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Supported by grants from the Swiss National Foundation for Scientific Research.     

Acetylcholinesterase,acid phosphatase,and succinic dehydrogenase in the hypothalamic magnocellular nuclei after serotonin administration

Zusammenfassung Es wurde histochemisch festgestellt, dass Serotonin eine mässige Steigerung der Acetylcholinesterase- und sauren Phosphataseaktivität des Nucleus supraopticus und Nucleus paraventricularis bewirkt. Es wird an eine Aktivierung des N. supraopticus und N. paraventricularis durch Serotonin gedacht.

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Aided by a grant from the Sigrid Jusèlius Stiftelse.     

Das Nebenhodengangepithel der Ratte nach Hypophysektomie und nach Androgensubstitution

Summary The epithelium of the epididymal duct (corpus region) of the rat after hypophysectomy and after androgen substitution has been examined by light and electron microscopy. The epithelium consists of 3 different cell types: principal, accessory (Nebenzellen), and basal cells. The characteristics of these cells disappear after hypophysectomy and redifferentiate after androgen application. The alterations of the principal and accessory cells in course of time (from the 1st week up to 9 weeks after injection of 20 mg testosterone propionate) are the subject of this report.