In vivo incorporation of14C-phenylalanine into ascidian tunichrome

Ascidia ceratodes exposed to¹⁴C-phenylalanine in the surrounding seawater incorporates the radiolabel into newly biosynthesized tunichrome molecules. Radioactivity can be detected in tunichrome extracted from circulating blood cells within one day following initial exposure to the radiolabel; weak activity (4 Ci/mol tunichrome=22 nmol phenylalanine/mol tunichrome) is detected in 1 to 10 days; significantly higher amounts of radiolabel (57 Ci/mol tunichrome=318 nmol phenylalanine/mol tunichrome) appear 20 days after seawater exposure. Therefore, phenylalanine can function as a precursor in the biosynthesis of tunichrome.     

In vivo incorporation of 14C-phenylalanine into ascidian tunichrome.

Ascidia ceratodes exposed to 14C-phenylalanine in the surrounding seawater incorporates the radiolabel into newly biosynthesized tunichrome molecules. Radioactivity can be detected in tunichrome extracted from circulating blood cells within one day following initial exposure to the radiolabel; weak activity (less than or equal to 4 microCi/mol tunichrome = 22 nmol phenylalanine/mol tunichrome) is detected in 1 to 10 days; significantly higher amounts of radiolabel (57 microCi/mol tunichrome = 318 nmol phenylalanine/mol tunichrome) appear 20 days after seawater exposure. Therefore, phenylalanine can function as a precursor in the biosynthesis of tunichrome.     

Effect of aflatoxin B1 on the incorporation of14C-acetate into cholesterol by rat liver

Résumé L'administration d'aflatoxine B₁ (2 et 5 mg/kg, i.p., 24 h avant le sacrifice) a résulté en un abaissement de 80% de l'incorporation du l-¹⁴C-acétate en cholestérol par des coupes de tissu de foie. Le même traitement n'a pas altéré l'activité des drug metabolizing enzymes au niveau des microsomes du foie.     

Early incorporation of labelled palmitate into mouse lung

Résumé Le taux d'incorporation de l'acide palmitique marqué à l'hydrogène 3 dans les cellules des bronchioles terminales et des alvéoles du poumon de la souris, suggère que le surfactan pulmonaire est sécrété par les cellules deClara dans les bronchioles terminales.     

Effect ofβ-Aminoethylisothiuronium-bromide-hydrobromide on the acetate-1-14C incorporation into tissue lipids of irradiated rats

Zusammenfassung Einfluss von Bestrahlung auf die Lipidsynthese, wobei festgestellt wird, dass der Strahlungsschutzstoff AET die Lipidsynthese hemmt.     

The incorporation of14C-acetate into the lipids of vacuolated rat liver cells

Riassunto È stata studiata l'incorporazione dell'acetato-1-¹⁴C nei fosfolipidi, nel colesterolo e negli acidi grassi di sezioni di fegato normale e vacuolizzato di ratto. Essa non è variata, in nessuna delle frazioni lipidiche considerate, nelle sezioni di fegato colpito da degenerazione vacuolare. Si discutono i risultati in rapporto alle precedenti osservazioni sulla inibizione dell'incorporazione degli amino acidi marcati nelle proteine delle sezioni di fegato vacuolizzato.     

Effect of riboflavin deficiency on free amino acid nitrogen concentrations of liver,muscle and plasma

Zusammenfassung Männliche Albino-Ratten, 45 Tage bei riboflavinarmer Nahrung, zeigten erhöhten Gehalt freien Aminosäure-Stickstoffs in Leber, Muskel und Plasma. Die Erhöhung scheint durch eine gesteigerte Aktivität der Nebennierenrinde beim Riboflavinmangel herbeigeführt zu sein.     

In vitro incorporation of14C labeled precursors into swine coronary arterial phospholipids

Zusammenfassung Der Grad des Einbaus von¹⁴C-markierten Prekursoren in die Arterienphospholipide des Schweins war folgender: Cholin>Aethanolin>Serin> Glycerin>Format>Azetat. Bei Bebrütung von Arterien mit¹⁴C-Cholin oder¹⁴C-Aethanolamin trat ein deutlich erhöhter Einbau von¹⁴C in das Phosphatidylcholin auf.

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This investigation was supported by Grant No. 5R01-HE10172-03 from the National Heart Institute, U.S.P.H.S.     

The synthesis of stereoselectively labelled porphobilinogen and its incorporation into protoporphyrin-IX

Summary 11-(R)-²H porphobilinogen, stereospecifically labelled with deuterium in the aminomethylene group has been incorporated into protoporphyrin-IX by haemolysates of chicken erythrocytes. High field NMR spectroscopy confirms that the overall biochemical process is stereospecific, deuterium being retained at the -, -and -meso positions and lost from the -meso position.27 August 1986     

The synthesis of stereoselectively labelled porphobilinogen and its incorporation into protoporphyrin-IX

11-(R)-2H porphobilinogen, stereospecifically labelled with deuterium in the aminomethylene group has been incorporated into protoporphyrin-IX by haemolysates of chicken erythrocytes. High field NMR spectroscopy confirms that the overall biochemical process is stereospecific, deuterium being retained at the alpha-, gamma- and delta-meso positions and lost from the beta-meso position.     

Diurnal rhythm of choline-14C incorporation into lecithin in Ehrlich-Lettré ascites tumour cells

Zusammenfassung Es wird über den diurnalen Rhythmus des Cholin-Einbaues sowie des Gesamt-Lecithin-Gehaltes des glykogenfreien Ehrlich-Lettré Mäuse-Ascites-Tumors berichtet. 24stündige Hungerbehandlung der Mäuse löscht diesen Effekt, während cholinfreie Diät keinen Einfluss auf den rhythmischen Verlauf hat. Thymidin-Einbau in DNA und Mitoserate zeigen keinen diurnalen Rhythmus.

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Acknowledgments. The author wishes to thank Dr.C. Granzow from this institute for providing the data on the mitotic index. The excellent technical assistance ofO. Gilch is greatly appreciated.