Increase in cystathionine β-synthase activity in the liver of rats treated withl-ethionine

Résumé Une seule injection d'éthionine (400 mg/kg) provoque une augmentation significative de l'activité de la cystathionine -synthase du foie de rat. La méthionine empêche l'effect de l'éthionine, tandis que l'actinomycine D, le cycloheximide, la méthionine sulfoximine, la méthionine sulfona et l'ATP ne le modifient pas. In vitro, l'éthionine n'a aucune influence sur l'activité de la cystathionine synthase hépatique.

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This work was supported by the Serbian Medical Research Foundation.     

The effect of bile salts on thyroxine 5′-monodeiodination in rat liver homogenate

Summary Unconjugated and conjugated bile salts inhibited the conversion of thyroxine to 3,3,5 triiodothyronine in rat liver homogenate.This work was supported in part by a grant from the Imanaga Foundation, Nagoya, Japan.     

Ultrastructural localization of catalase and D-amino acid oxidase in ‘normal’ fetal mouse liver

Summary In the hepatocytes of normal fetal mice from mothers which were carriers of muscular dysgenesis, catalase and D-amino acid oxidase (DAAO) positive as well as negative peroxisomes were observed. DAAO reaction product was occasionally localized in patches around cell membranes and DAAO-positive peroxisomes were frequently observed near mitochondria.     

Increased inactivation of polysaccharide phosphorylase in liver homogenates from rats treated with 3,5,3′-triiodo-l-thyronine

Riassunto L'attività polisaccaride fosforilasica presente negli omogenati di fegato dei ratti trattati per 3 giorni con T-3 è sensibilmente diminuita; sono invece nettamente aumentate, in assenza di fluoruro, la trasformazione della formaa inb e, in presenza di fluoruro, l'inattivazione irreversibile dell'enzima. Nel fegato degli animali ipertiroidei la diminuzione dell'attività polisaccaride fosforilasica non sarebbe però dovuta all'esaltata inattivazione, ma alla minore concentrazione dell'enzima stesso.

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Dedicated to Prof.A. v. Muralt on the occasion of his 60th birthday.

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The following abbreviations are used: ATP, adenosine triphosphate; PPh, polysaccharide phosphorylase; IE, inactivating enzyme or phosphorylase phosphatase; Tris, Tris (hydroxymethyl) aminomethane; Pi, inorganic phosphate; T-3, 3,5,3-triiodo-l-thyronine.     

Changes in adenylate cyclase and 5′-nucleotidase activities in liver membranes from alloxan diabetic rats

Summary Liver membrane adenylate cyclase activity was significantly higher and 5-nucleotidase activity significantly lower in alloxan diabetic rats compared with normal rats.     

Loss of tryptophan pyrrolase cofactor from liver cytoplasmic structures of 3′-methyl-4-dimethylaminoazobenzene fed rats

Résumé L'ingestion du cancérogène 3-méthyl-4-diméthylaminoazobenzène pendant 40 jours inhibe fortement l'induction de la tryptophane pyrrolase du foie des rats causée par leL-tryptophane ou bien l'hydrocortisone. Les auteurs montrent que cet effet est dû à la perte du cofacteur de la tryptophane pyrrolase des mitochondries et des microsomes des animaux soumis au régime alimentaire cancérogène.     

Purification of α-ketoaldehyde dehydrogenase from the human liver and its possible significance in the control of glycation

Summary Alfa-ketoaldehyde dehydrogenase, which was extracted and purified from human livers, may act on carbonyl compounds, such as 3-deoxyglucosone, and be involved in the control of glycation (Maillard reaction) in the body.     

The presence of RNA of the A–U type in citrate nuclei isolated from rabbit liver cells

Zusammenfassung Die in 5% iger Zitronensäure isolierten Kaninchenleberkerne enthalten eine minimale Fraktion von RNS, die sich durch ihren Gehalt an Basen der DNS annähert (A+U/G+C>1). Diese RNS wird während der Extraktion mit dem 6% igen Natrium-p-Amino-salicylat und dem Phenol zusammen mit der DNS und RNS vom G+C-Typ gewonnen.     

The effects of vitamin A nutritional status on microsomal lipid peroxidation and α-tocopherol level in rat liver

Summary In vitamin A-deficient rats, liver glutathione peroxidase activity was decreased, -tocopherol content was strongly enhanced, but microsomal liquid peroxidation remained unchanged.     

In vitro effects of 1,2,3,4-tetrahydro-β-naphtylamine (THNA) on succinate oxidation by rat liver homogenates

Riassunto Il consumo di ossigeno e la decolorazione del Bleu di Metilene dovuti all'ossidazione del succinato da parte di omogenati di fegato di ratto, appaiono nettamente aumentati in presenza di-tetraidronaftilammina. Viene prospettata la eventualità che tale sostanza sia in grado di esercitare un'azione attivante «diretta» sul sistema succino-deidrogenasico.     

Quantitative investigation of the P and N loss in the rat liver when using various media in the ‘freeze-substitution’ technique

Résumé Les auteurs ont examiné les possibilités de diminution du contenu en azote et phosphore et de la masse sèche au cours de la congelation-dissolution des tissus. La diminution la plus marquée a été observée après l'usage de méthanol. Tandis qu'avec l'acétone elle est insignifiante.     

5′-Nucleotidase activity in liver homogenates of rats treated with CCl4, colchicine,cycloheximide, emetine,ethanol, ethionine and 5-fluorotryptophan

Summary 5-Nucleotidase activity, an enzyme marker of the plasma membranes, increases in female rat liver homogenates following ethionine administration, while homogenates from males show no changes. Treatment with CCl₄, colchicine, cycloheximide, emetine, ethanol and 5-fluorotryptophan does not significantly modify the 5-nucleotidase activity of liver homogenates of either female or male rats.