The effect of dihydroergotamine on the phosphodiesterase activity of cat grey matter

Zusammenfassung Es wurde die Hemmung der Phosphodiesterase PEase durch DHE untersucht. Die Inhibition durch DHE liegt in derselben Grössenordnung wie diejenige der Methylxanthine. Die Dosisabhängigkeit der PEase-Hemmung durch DHE ist nahezu linear zu den in Dekaden aufgetragenen Konzentrationen.     

Inhibition of reserpine-induced PGO waves in the cat by ergot derivatives

Summary The number of reserpine-induced PGO waves in the cat is decreased by administration of ergot derivatives. The inhibition is dose-dependent and the various ergot derivatives show differing potencies. The action of the ergot derivatives may result from stimulation of central serotonin receptors. In addition, possible involvement of dopaminergic systems is discussed.     

Inhibition of secretion and secretory potentials in the submandibular gland of the cat by acetazolamide

Zusammenfassung Es wird eine Hemmung der Speichelflussrate in der Submandibularisdrüse der Katze durch den Kohlensäureanhydratasehemmstoff Acetazolamid hervorgerufen und gleichzeitig eine Hemmung der sekretorischen Potentialunterschiede über Azinuszellmembrane gemessen. Die Sekretionshemmung liesse sich durch die Hemmung der sekretorischen Potentiale, die ein Mass für einen aktiven Anionentransport ist, erklären.

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We are greatly indebted to Dr. N. A.Thorn for his valuable help and criticism throughout this study.

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The work was supported by a grant from the Danish State Research Foundation. — We thank Dr. C.Crone for loan of various equipment supplied by the F. L. Smidth Foundation and the Danish State Research Foundation.     

Uptake of labelled histones by isolated perfused rat liver and by various organs of the intact mouse

Résumé Des histones marquées au H³ ont été administrées à des souris par voie intrapéritonéale. La pénétration d'histones dans le foie isolé en perfusion est rapide. Les noyaux contiennent une quantité plus ou moins proportionnelle à leur volume dans la cellule et la majorité de l'activité a pu être isolée comme histones liées à la chromatine.     

Differences between the soluble mitochondrial proteins in various organs of the rat

Résumé Les phérogrammes obtenus après électrophorèse en acrylamide des protéines mitochondriales solubles du rein, du foie et du cur, montrent des différences dans ces 3 organes. Le profil électrophorétique est reproductible et caractéristique pour la fraction mitochondriale de ces organes.     

Inhibition of the growth of cariogenic bacteria in vitro by plant falvanones

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified fromSophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2,4-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 g/ml.     

Chemotaxis of rabbit macrophages in vitro: Inhibition by drugs

Summary Chemotaxis of rabbit macrophages was inhibited in vitro by phenylbutazone and sodium salicylate, but not by other antiinflammatory agents. Other inhibitory compounds were colchicine, vincristine, PHA, Con A, iodoacetic acid, cytochalasin B, and EDTA. Some of these in vitro results contrast apparently with in vivo effects.     

Inhibition of in vitro RNA synthesis by hycanthone,oxamniquine and praziquantel

Summary The schistosomicides, hycanthone, oxamniquine and praziquantel, were found to inhibit the in vitro RNA synthesis using isolated hamster liver nuclei. Preincubation of the nuclei with these drugs revealed that the inhibitory effect of oxamniquine was irreversible and progressed with time, whereas that of hycanthone and parziquantel was reversible. On the other hand, hycanthone and praziquantel have a high affinity for DNA but oxamniquine does not. The data indicate that the mechanism of inhibition by oxamniquine is different from that of hycanthone and praziquantel.     

Pyramidal activation of interneurones of various spinal reflex arcs in the cat

Résumé La stimulation du cortex sensori-moteur chez le chat facilite toutes actions synaptiques — excitatrices ou inhibitrices — qui sont provoquées dans les motoneurones par l'intermédiaire d'un ou de plusieurs interneurones. Ces actions peuvent prendre naissance dans des fibres afférentes d'origine musculaire I-a, I-b, II ou III, d'origine cutanée ou dans des fibres à seuil élevé provenant d'une jointure.L'effet observé dépend de la mise en action du faisceau pyramidal qui facilite le fonctionnement de tous les interneurones intercalés dans les arcs réflexes mentionnés.     

Cholesterol content and cholesterol esterifying activity of various organs in guinea pigs

In various organs of the guinea pig, the total cholesterol content of an organ was significantly correlated with the percentage of esterified cholesterol present in this organ. Cholesterol esterifying capacity was shown in most organs, with highest activities in the adrenals, the spleen and the liver. The significant correlation found between the cholesteryl ester content of an organ and its acyl cholesterol acyltransferase activity suggests a possible role of this enzyme in determining the level of the total and esterified cholesterol in a tissue.     

Cholesterol content and cholesterol esterifying activity of various organs in guinea pigs

Summary In various organs of the guinea pig, the total cholesterol content of an organ was significantly correlated with the percentage of esterified cholesterol present in this organ. Cholesterol esterifying capacity was shown in most organs, with highest activities in the adrenals, the spleen and the liver. The significant correlation found between the cholesteryl ester content of an organ and its acyl cholesterol acyltransferase activity suggests a possible role of this enzyme in determining the level of the total and esterified cholesterol in a tissue.This work was supported by a grant Crédit aux Chercheurs du Fonds National de la Recherche Scientifique of Belgium.Acknowledgments. I am indebted to Prof. C. Harvengt for his stimulating interest and helpful suggestions. I wish to thank Y. van Nieuwenhuyze and J. Costermans for their valuable laboratory assistance and Dr H. Baudon for pathological studies.