scholarly journals Rabbit liver acetyl-CoA synthetase

1978 ◽  
Vol 175 (2) ◽  
pp. 757-759 ◽  
Author(s):  
G Woodnutt ◽  
D S Parker
Keyword(s):  
Subcellular Fractions ◽  
Rabbit Liver ◽  
Acetyl Coa ◽  
Assay Medium ◽  
Liver Homogenates

Acetyl-CoA synthetase (EC 6.2.1.1) was assayed in subcellular fractions of rabbit liver homogenates. The activity was located almost exclusively in the cytosol. There was no decrease in activity when butyrate or propionate (each at 5–20 mM) were added to the assay medium.

scholarly journals Studies on protein binding of antibiotics. IV. Effect of the binding of drug to 100,000*g supernatant fluid of rabbit liver homogenates on urinary excretion.

1982 ◽  
Vol 35 (11) ◽  
pp. 1603-1609
Author(s):  
YASUO WATANABE ◽  
RIEKO KITAYAMA ◽  
TOSHIO HAYASHI ◽  
YOSHIFUMI NAKASHIMA ◽  
MASASHI NOGUCHI ◽  
...  
Keyword(s):  
Protein Binding ◽  
Urinary Excretion ◽  
Rabbit Liver ◽  
Supernatant Fluid ◽  
Liver Homogenates

scholarly journals A comparison of glucoside formation by liver preparations from the rabbit and the mouse

1974 ◽  
Vol 142 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Rosalind S. Labow ◽  
Donald S. Layne
Keyword(s):  
Mouse Liver ◽  
The Other ◽  
Rabbit Liver ◽  
Ph Optimum ◽  
Liver Homogenates

Liver homogenates from mice and from rabbits transfer glucose from UDP-[6-3H]glucose, at pH7.0, to oestradiol-17α, oestradiol-17β, oestradiol-17α 3-glucuronide, p-nitrophenol and diethylstilboestrol. In the rabbit the phenolic steroids were better substrates than p-nitrophenol for the glucosyltransferase, whereas the reverse was true in the mouse. At pH8.0, rabbit liver, but not mouse liver, transferred glucose to oestradiol-17α 3-glucuronide in better yield than that at pH7.0. Evidence is presented for the presence of two glucosyltransferases in rabbit liver. One of these has a pH optimum at about 8.0, and is highly specific for oestradiol-17α 3-glucuronide, whereas the other, which has a pH optimum at about 7.0, is similar in this respect to the transferase in mouse liver.

Sex- and species-related differences in the biotransformation of isosorbide dinitrate by various tissues of the rabbit and rat

1987 ◽  
Vol 65 (7) ◽  
pp. 1478-1483 ◽  
Author(s):  
G. S. Tam ◽  
G. S. Marks ◽  
J. F. Brien ◽  
K. Nakatsu
Keyword(s):  
Skeletal Muscle ◽  
Sex Difference ◽  
Isosorbide Dinitrate ◽  
Species Difference ◽  
Rabbit Liver ◽  
Male Rat ◽  
Tissue Homogenate ◽  
Male Rabbit ◽  
Tissue Homogenates ◽  
Liver Homogenates

The biotransformation of isosorbide dinitrate (ISDN) by various tissues of the rabbit and rat was examined. Incubation of 2 × 10−7 M ISDN at 37 °C with tissue homogenates of liver, lung, kidney, intestine, skeletal muscle, aorta, and erythrocytes from the rabbit and rat resulted in a significant disappearance of ISDN after a 30-min incubation (also, 5-min incubation for liver). The disappearance of ISDN in each tissue homogenate was accompanied by an equimolar production of the mononitrate metabolites, isosorbide-2-mononitrate (2-ISMN) and isosorbide-5-mononitrate (5-ISMN), with the exception of liver homogenates where the loss of ISDN could not be accounted for by mononitrate formation. The relative rate of ISDN disappearance in various tissue homogenates was for the male rabbit, liver > lung ≈ intestine > kidney > erythrocytes ≈ skeletal muscle ≈ aorta; for the female rabbit, liver > kidney ≈ lung ≈ intestine > erythrocytes ≈ skeletal muscle ≈ aorta; and for the male rat, liver > intestine > erythrocytes > skeletal muscle > lung ≈ kidney. A sex difference in the percent disappearance of ISDN was observed in homogenates of lung and intestine from male and female rabbits. In addition, a sex difference in the ratio of metabolite (2-ISMN/5-ISMN) formed by denitration of ISDN was seen in homogenates of lung, skeletal muscle, and erythrocyte lysate. There was a species difference between the male rabbit and male rat, with respect to the loss of ISDN exhibited during incubation of ISDN with liver homogenates for 5 min; this was also observed for homogenates of lung, kidney, and intestine during a 30-min incubation. In addition, a similar species difference was observed for metabolite ratios obtained from these incubations. These results indicate that biotransformation of ISDN by liver and extrahepatic tissues may contribute to the high systemic clearance of this drug. The observed sex and species differences in the rate of ISDN disappearance and the metabolite ratio (2-ISMN/5-ISMN) in the various tissues may be due to hormonal and (or) genetic differences.

USE OF LIVER HOMOGENATES FOR STUDIES ON THE INTRACELLULAR SITE OF UBIQUINONE BIOSYNTHESIS

1966 ◽  
Vol 44 (12) ◽  
pp. 1615-1624 ◽  
Author(s):  
W. E. J. Phillips ◽  
M. Hidiroglou ◽  
G. Hatina
Keyword(s):  
Rat Liver ◽  
Mevalonic Acid ◽  
Subcellular Fractions ◽  
Hydroxybenzoic Acid ◽  
Saponifiable Matter ◽  
Liver Homogenates ◽  
Intact Rats

Mevalonic acid was incorporated into the ubiquinone and sterol fractions of rat-liver homogenates. The incorporation of mevalonate was increased approximately 10-fold in the total non-saponifiable matter including sterol by use of the in vitro homogenate system as compared with intact rats. The incorporation into the ubiquinones was decreased. The addition of potential ring precursors, p-hydroxybenzoic acid, L-phenylalanine, or L-tyrosine to the homogenate system did not increase incorporation of mevalonate into ubiquinone.Incubation of subcellular fractions from rat-liver homogenates demonstrated that supernate plus either mitochondria or microsomes were necessary for the biosynthesis of ubiquinone.

Topography of apolipoprotein B in subcellular fractions from rabbit liver

1993 ◽  
Vol 21 (2) ◽  
pp. 126S-126S
Author(s):  
JANE WILKINSON ◽  
JOAN A. HIGGINS ◽  
PIETER H. E. GROOT ◽  
ERMANNO GHERARDI ◽  
DAVID E. BOWYER
Keyword(s):  
Apolipoprotein B ◽  
Subcellular Fractions ◽  
Rabbit Liver

scholarly journals Determination of the intracellular distribution and pool sizes of apolipoprotein B in rabbit liver

1992 ◽  
Vol 288 (2) ◽  
pp. 413-419 ◽  
Author(s):  
J Wilkinson ◽  
J A Higgins ◽  
P H E Groot ◽  
E Gherardi ◽  
D E Bowyer
Keyword(s):  
Endoplasmic Reticulum ◽  
Apolipoprotein B ◽  
Intracellular Distribution ◽  
Subcellular Fractions ◽  
Rabbit Liver ◽  
Very Low Density Lipoproteins ◽  
Apo B ◽  
Golgi Region ◽  
Membrane Bound ◽  
Vldl Assembly

We have investigated the intracellular distribution of apolipoprotein B (apo B) in rabbit liver by immunoblotting, radioimmunoassay (r.i.a.) and enzyme-linked immunoassay (e.l.i.s.a.). Apo B100 was detected in total microsomes, rough microsomes, smooth microsomes, trans-enriched Golgi and cis-enriched Golgi and membrane and cisternal-content subfractions prepared from these fractions. There was also evidence of degradation of apo B100 in the Golgi membrane fractions. The amount of apo B in the subcellular fractions detected by competitive r.i.a. or e.l.i.s.a. ranged from 1.5 micrograms/mg of protein in the rough endoplasmic reticulum to 13 micrograms/mg of protein in the trans-Golgi fraction. Using internal standards (NADPH-cytochrome c reductase for the endoplasmic reticulum and galactosyltransferase for the Golgi membranes) it was calculated that all the apo B of liver is recovered within the secretory compartment, with 63% of the total apo B in the endoplasmic reticulum and the remainder in the Golgi. When the subcellular fractions were separated into membranes and cisternal contents, 60%, 50%, 60% and 30% of the total apo B was recovered in the membrane of the rough microsomes, smooth microsomes, cis-Golgi and trans-Golgi respectively. Using competitive e.l.i.s.a. we found that the membrane-bound form of the apo B was exposed at the cytosolic surface of the intact subcellular fractions. These observations are consistent with a model for assembly of very-low-density lipoproteins (VLDL) in which newly synthesized apo B is incorporated into a membrane-bound pool and a lumenal pool. The membrane-bound pool not used for VLDL assembly may be degraded, possibly in the Golgi region.

Studies on Liver Factors which Exert an Inhibitory Effect on Platelet Aggregation

1971 ◽  
Vol 26 (01) ◽  
pp. 135-144
Author(s):  
W Rogowski ◽  
W GaŁasiński ◽  
E Bańkowski ◽  
W Rzeczycki
Keyword(s):  
Platelet Aggregation ◽  
Inhibitory Effect ◽  
Probable Mechanism ◽  
Rabbit Liver ◽  
Nucleotides And Nucleosides ◽  
Liver Homogenates ◽  
Active Substances

SummaryThe inactivating effect of rabbit liver homogenates on platelet aggregation was investigated.The active substances were found in a nonprotein fraction of the liver homogenates. They were separated and identified as nucleotides and nucleosides. It was found that the platelet aggregation inhibiting substances obtained from the liver, inactivated the platelet aggregating factors, such as ADP, thrombin and collagen. Nucleosides and nucleotides were chromatographically separated from the liver homogenates, and their effect examined on the platelet aggregating factors. The probable mechanism of their inactivation and their pathophysiological significance are discussed.

scholarly journals Treatment of rats with glucagon or mannoheptulose increases mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase activity and decreases succinyl-CoA content in liver

1989 ◽  
Vol 262 (1) ◽  
pp. 159-164 ◽  
Author(s):  
P A Quant ◽  
P K Tubbs ◽  
M D Brand
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Ketone Bodies ◽  
Liver Mitochondria ◽  
Mitochondrial Activity ◽  
Acetyl Coa ◽  
Total Enzyme Activity ◽  
Liver Homogenates ◽  
Rat Livers ◽  
Total Enzyme

1. The activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (EC 4.1.3.5) in extracts of rapidly frozen rat livers was doubled in animals treated in various ways to increase ketogenic flux. 2. Some 90% of the activity measured was mitochondrial, and changes in mitochondrial activity dominated changes in total enzyme activity. 3. The elevated HMG-CoA synthase activities persisted throughout the isolation of liver mitochondria. 4. Intramitochondrial succinyl-CoA content was lower in whole liver homogenates and in mitochondria isolated from animals treated with glucagon or mannoheptulose. 5. HMG-CoA synthase activity in mitochondria from both ox and rat liver was negatively correlated with intramitochondrial succinyl-CoA levels when these were manipulated artificially. Under these conditions, the differences between mitochondria from control and hormone-treated rats were abolished. 6. These findings show that glucagon can decrease intramitochondrial succinyl-CoA concentration, and that this in turn can regulate mitochondrial HMG-CoA synthase. They support the hypothesis that the formation of ketone bodies from acetyl-CoA may be regulated by the extent of succinylation of mitochondrial HMG-CoA synthase.

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