Biliary excretion of sulfobromophthalein in isolated perfused livers from normal and spironolactone-treated rats

Summary Bile flow and biliary excretion of sulfobromophthalein (BSP) was examined in isolated perfused livers from normal and spironolactone(SP)-treated rats. BSP biliary excretion contributed to the bile production in both groups. Moreover SP increased BSP biliary excretion but transfer of dye from plasma into liver was not affected.Acknowledgments. This work was supported by a grant from Consejo Nacional de Investigaciones Científicas y Técnicas República Argentina (EFIHER-CONICET). Isolated rat liver preparations were performed by Miss Graciela Patricia Rodriguez. The assistance of Carlos Guillermo Grieve is also gratefully acknowledged.     

Effects of dosage and cadmium pretreatment on the binding of cadmium in rat bile.

The effects of dosage and of cadmium pretreatment on the binding of cadmium in rat bile were studied. With increasing dose a higher cumulative biliary excretion of Cd was observed and a higher percentage of the Cd was excreted in a low-molecular-weight form. On the other hand, after cadmium pretreatment, a decrease in the cumulative biliary excretion of cadmium was observed but a greater percentage of that excreted into the bile was bound to high molecular weight compounds.     

Covalent binding of aflatoxin B1 to liver DNA in rats pretreated with ethanol

Male Fischer F-344 rats were given ethanol in the drinking water and/or by single oral administration. Following this, the animals received p.o. 100 ng/kg of the hepatocarcinogen [3H]aflatoxin B1 (AFB1). 24 h later, the level of DNA-bound AFB1 was determined in the liver and was found not to be affected by any type of ethanol pretreatment. A cocarcinogenic effect of ethanol in the liver is therefore unlikely to be due to an effect on the metabolic activation inactivation processes governing the formation of DNA-binding AFB1 metabolites.     

Covalent binding of aflatoxin B1 to liver DNA in rats pretreated with ethanol

Summary Male Fischer F-344 rats were given ethanol in the drinking water and/or by single oral administration. Following this, the animals received p.o. 100 ng/kg of the hepatocarcinogen [³H]aflatoxin B₁ (AFB₁). 24 h later, the level of DNA-bound AFB₁ was determined in the liver and was found not to be affected by any type of ethanol pretreatment. A cocarcinogenic effect of ethanol in the liver is therefore unlikely to be due to an effect on the metabolic activation and inactivation processes governing the formation of DNA-binding AFB₁ metabolites.To whom correspondence should be addressed.Acknowledgment. We thank the European Science Foundation for the Toxicology Research Fellowship awarded to M.M.     

Tissue distribution and nucleic acid binding of chlorambuci-3H in tumor-bearing rats

Summary In tumour and normal rat tissues prolonged alkylation of DNA and RNA by chlorambucil-³H occurs over periods of 24 h. It is suggested that this may indicate the slow release of an alkylating moiety from an intracellular drugmacromolecule complex.     

Effects of hypophysectomy and thyroidectomy on the glycogen depletion in livers of rats treated with thioacetamide

Zusammenfassung Die Verarmung von Glykogen in der Leber als Ausdruck der toxischen Wirkung von Thioacetamid kann durch Hypophysektomie oder Thyroidektomie verhindert werden.     

Subcellular distribution of tyrosine hydroxylase and monoamine oxidase in the bovine caudate nucleus

Zusammenfassung Die subzelluläre Lokalisation von Tyrosin-Hydroxylase und Monoaminoxydase im Nucleus caudatus des Rindergehirns wurde untersucht. Tyrosin-Hydroxylase fand sich grösstenteils in den Synaptosomen, den Mikrosomen und dem Zytoplasma. Eine bedeutende Aktivität von Monoaminoxydase war in den Mitochondrien vorhanden.     

The distribution of glucose and methyl-glucose between the liver and plasma in normal and insulin injected rats

Zusammenfassung Es wurde gefunden, dass 3-Methyl-Glukose (MEG) sich in 85% der gesamten Gewebeflüssigkeit der Rattenleber löst. Ist Glukose in gleicher Plasmamenge enthalten, so ist die berechnete Konzentration in der Leberzellflüssigkeit doppelt so hoch. Bei Insulinhypoglykämie stieg dieses Verhältnis weiter an, ohne aber eine Veränderung im Verteilungsvolumen von MEG zu ergeben. Die Leberzellmembran scheint die Penetration der Glukose aus der Zelle zu verzögern.

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The financial support of The Medical Research Council of Canada and the Banting Foundations as well as the skilled technical help of Mrs.S. Waterfield is gratefully acknowledged.     

Succinoxidase activity of mitochondria isolated from the liver of rats after partial hepatectomy and hypophysectomy

Zusammenfassung Bei den 24 und 48 h nach partieller Hepatektomie (Resektion von 65–70% der Leber) aus der Rattenleber isolierten Mitochondrien wurde eine Abnahme der sukzinoxydaseaktivität beobachtet. Dasselbe wurde auch bei Ratten beobachtet, bei welchen gleichzeitig mit der partiellen Hepatektomie eine Hypophysektomie durchgeführt wurde. Die Veränderung der Sukzinoxydaseaktivität ist nicht auf eine Erniedrigung der Mitochondrienzahl pro Gewichtseinheit Leber zurückzuführen.     

Kinetics of the pulmonary clearance of inhaled cadmium and its accumulation in rat liver and kidneys]

Pulmonary clearance rate of cadmium (Cd), inhaled in the form of an aerosol of Cd acetate, is very slow (half-life 53 days). However, results demonstrate that an important part of Cd cleared from the lung is recovered in liver and kidney. Liver binds this metal rapidly but to a limited extent, whereas renal accumulation is slow but continuous throughout the three months following exposure.     

The formation of flavin-adenine dinucleotide in liver cells prepared from normal and alloxan diabetic rats

Riassunto Viene studiata la formazione del flavin-adenin dinucleotide (FAD) da parte di cellule di fegato di animali normali e diabetici per allossana a partire da flavin mononucleotide (FMN).Le cellule dell'animale normale possono sintetizzare il FAD direttamente dal FMN, mentre le cellule dell'animale diabetico possono effettuare questa sintesi dal FMN, solo se viene aggiunto anche ATP.Tale sintesi è possibile solo se viene conservata l'integrità cellulare. Viene descritto un procedimento per la preparazione delle cellule isolate di fegato.     

Oxygen consumption and biosynthetic function in perfused liver from rats at different stages of development

Changes in mitochondrial function were studied in perfused liver from rats aged 24 – 365 days. Oxygen consumption together with the rates of gluconeogenesis, urea synthesis and ketogenesis were determined. Basal mitochondrial respiration as well as the ability of the liver to synthesize glucose, urea and ketone bodies declined from 24- to 365-day-old rats. On the other hand, on transition from 24 to 60 days the liver oxidation rate of hexanoate, sorbitol and glycerol is enhanced, but not of ketone bodies or palmitate. Our results show that the transition from weaning to middle age is accompanied by defined changes in hepatic substrate oxidation. From the observed time course of the decrease in basal and substrate-stimulated oxygen consumption, it is concluded that in rat liver cells a decline in respiratory chain function, long-chain fatty acid and ketone body metabolism, gluconeogenesis and ureogenesis occurs at a relatively early life stage. Received 19 June 1998; received after revision 11 September 1998; accepted 11 September 1998     

Metabolism of pyridoxal phosphate in the liver of hypo- and hyperthyroid rats

Riassunto È stata determinata nel fegato di ratti normali, ipotiroidei ed ipertiroidei l'attività degli enzimi che portano alla sintesi del piridossalfosfato, la piridossalcinasi e la piridossaminfosfatoossidasi, e del primo enzima che ne catalizza la demolizione, una fosfatasi. In condizioni di ipertiroidismo sono aumentate la piridossalcinasi e la fosfatasi, mentre la ossidasi è invariata; nell'ipotiroidismo invece non si osservano modificazioni significative. La quantità di acido piridossico escreta con l'urina è diminuita nell'ipotiroidismo e aumentata nell'ipertiroidismo.

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This investigation was supported by Research Grant No. AM-05676 from the United States Public Health Service.     

Pantothenic acid distribution and protein synthesis in the particulate fractions of rat liver

Zusammenfassung Ratten wurden während 10 Wochen mit durch Pantothensäure angereicherte Nahrung oder mit Pantothensäure-Mangeldiät gefüttert. Im Anschluss daran wurden die durch Differentialzentrifugation gewonnenen Fraktionen von Leberhomogenat auf ihren Protein- und Panthothensäuregehalt untersucht. Die Resultate deuten darauf hin, dass Panthothensäure die Synthese von Leberproteinen, insbesondere in der Überstands-Fraktion, stimuliert.

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Acknowledgement. Authors thank Dr. (Mrs.)A. Venkataraman and Dr.N. K. Dutta, Director of this Institute, for their encouragement and interest, and they are also grateful to Dr.M. J. Modak for his kind help.     

Pre- and postnatal distribution of lipids in the liver of genetic diabetic mice.

Triglycerides, phospholipids, cholesterol and cholesterol esters were determined by thin layer chromatography in the fetal and neonate livers of normal (Swiss albino) and genetic diabetic (KK) mice. In general, the lipids were elevated in the fetal liver of the KK mice. Despite this elevation in liver lipids, no increase in the weight of the newborn was observed.     

Mitochondrial size distribution analysis in the soleus muscle of trained and aged rats

Résumé Analyse par microscopie électronique du muscle jambier postérieur chez des rats âgés de 50 jours, adultes, avec ou sans entraînement physique et âgés de 720 jours. Les résultats laissent supposer l'existence d'une taille optimum pour les mitochondries de même que la présence de mitochondries avant-courrières.     

Effect of latent iron deficiency on the levels of iron,calcium, zinc,copper, manganese,cadmium and lead in liver,kidney and spleen of growing rats

Summary Feeding a marginally low iron content diet (18–20 mg iron/kg diet) to weaned (21-day-old) rats for 8 weeks produced a significant decrease in liver non-heme iron (66%, p<0.001) but no change in blood hemoglobin. Total iron contents of liver (56%, p<0.01), spleen (20%, p<0.05), and kidney (19%, p<0.05) were also found to decrease along with increased zinc, copper, calcium, manganese lead and cadmium in various organs. The magnitude of alteration of a metal was different in different organs. However, liver was found to be the most affected organ. Two weeks of rehabilitation with iron-sufficient diet (390 mg iron/kg diet) normalized these altered levels.