Fructose 1,6-bisphosphatase in rat liver cytosol: Activation after glucagon treatment in vivo and inhibition by fructose 2,6-bisphosphate in vitro

1981 ◽  
Vol 101 (1) ◽  
pp. 104-111 ◽  
Author(s):  
Stéphanie Mörikofer-Zwez ◽  
Franziska B. Stoecklin ◽  
Paul Walter
Keyword(s):  
Rat Liver ◽  
Liver Cytosol ◽  
Fructose 1,6 Bisphosphatase ◽  
Rat Liver Cytosol

scholarly journals Heterogeneity and properties of hepatic dexamethasone-binding proteins

1979 ◽  
Vol 180 (1) ◽  
pp. 187-193 ◽  
Author(s):  
S L H Liu ◽  
T E Webb
Keyword(s):  
Rat Liver ◽  
Binding Proteins ◽  
Binding Protein ◽  
Novikoff Hepatoma ◽  
Liver Cytosol ◽  
Activated Complex ◽  
Simple Dissociation ◽  
Rat Liver Cytosol

Evidence from experiments in vivo and in vitro is presented for the presence of three species of dexamethasone-binding proteins in rat liver, which are identified by chromatography on Sepharose 6B or by isoelectric focusing. Although two of these species (DI and DII) possess properties characteristic of a true receptor, the third binding protein (i.e. DIII), which migrates most slowly on Sepharose 6B, but has stability properties similar to protein DII, exhibits a 3-fold lower affinity for dexamethasone and the activated complex neither binds to DNA-cellulose nor translocates to the nucleus. Only the predominant liver receptor (DI), which is eluted first from Sepharose 6B, is present in Novikoff-hepatoma cytosol, suggesting that the major and minor species are not interconverted through simple dissociation during their isolation. The binding activities of all three species in the liver cytosol increase approx. 2-fold in vivo after adrenalectomy and show a transient 2-fold fall in vivo after the administration of cortisol. These changes in vivo in protein DIII shows a marked lag compared with those in proteins DI and DII, which change in parallel. It is therefore proposed that rat liver cytosol contains two dexamethasone receptors and a dexamethasone-binding protein that may be derived from these receptors.

Studies on the Biosynthesis of Flavin Nucleotides from 2-14C-Riboflavin by Rat Liver and Kidney

1973 ◽  
Vol 51 (6) ◽  
pp. 772-782 ◽  
Author(s):  
A. G. Fazekas ◽  
T. Sandor
Keyword(s):  
Rat Liver ◽  
Flavin Adenine Dinucleotide ◽  
Total Radioactivity ◽  
Flavin Mononucleotide ◽  
Time Intervals ◽  
Adult Rats ◽  
Liver And Kidney ◽  
Rat Liver Cytosol

2-14C-Riboflavin was injected subcutaneously into young adult rats to study the biosynthesis of flavin mononucleotide (FMN) and flavin–adenine dinucleotide (FAD) in the liver and kidneys. Animals were sacrificed at different time intervals following the administration of labelled riboflavin (RF), and radioactive flavins were determined in their tissues by a newly devised method. Both tissues accumulated radioactive riboflavin rapidly and peak levels were obtained at 90 min after the injection, when over 80% of the total radioactivity of the liver was present in FAD. At this time the liver contained 17% of the injected dose of 2-14C-RF. The kidneys contained relatively high quantities of free RF due to the concentration and urinary excretion of the vitamin.Analysis of subcellular fractions of the liver of animals injected with 2-14C-RF revealed that most of the radioactivity was present in mitochondria and nuclei. The flavin nucleotides of rat liver cytosol became progressively associated with macromolecules in vivo. However, there was no significant binding of free RF by macromolecules in blood plasma or liver cytosol.Kinetic studies and incubations with liver slices indicated that RF freely diffuses into the liver cells, is rapidly converted into FAD, and becomes attached to apoenzymes. The tissue uptake of RF and FMN formation is considerably influenced by the concentration of RF present in the system, both in vivo and in vitro.

A Proteomic Analysis of Bromobenzene Reactive Metabolite Targets in Rat Liver Cytosol in Vivo

2007 ◽  
Vol 20 (3) ◽  
pp. 511-519 ◽  
Author(s):  
Yakov M. Koen ◽  
Natalia V. Gogichaeva ◽  
Michail A. Alterman ◽  
Robert P. Hanzlik
Keyword(s):  
Rat Liver ◽  
Proteomic Analysis ◽  
Reactive Metabolite ◽  
Liver Cytosol ◽  
Rat Liver Cytosol

scholarly journals Reduction of disulphide bonds in proteins mixed disulphides catalysed by a thioltransferase in rat liver cytosol

1975 ◽  
Vol 149 (3) ◽  
pp. 785-788 ◽  
Author(s):  
B Mannervik ◽  
K Axelsson
Keyword(s):  
Glutathione Reductase ◽  
Rat Liver ◽  
Direct Reduction ◽  
Liver Cytosol ◽  
Disulphide Bonds ◽  
Enzymic Reaction ◽  
Spontaneous Reaction ◽  
Rat Liver Cytosol

The reduction of mixed disulphides of some proteins and GSH [Protein(-SSG)n] is accomplished with GSH as a reductant and a thioltransferase from rat liver as a catalyst, thus: See article. The spontaneous reaction is negligible in comparison with the enzymic reaction in vivo, and any direct reduction with glutathione reductase is not detectable with the substrates used. The reduction is only indirectly dependent on NADPH, which is required for the regeneration of GSH from GSSG. Other protein disulphides apparently are reduced via analogous GSH-dependent reactions

scholarly journals Studies on the metabolism of rat liver copper-metallothionein

1985 ◽  
Vol 227 (3) ◽  
pp. 903-908 ◽  
Author(s):  
R K Mehra ◽  
I Bremner
Keyword(s):  
Rat Liver ◽  
Half Life ◽  
Pulse Labelling ◽  
Turnover Rates ◽  
Liver Cytosol ◽  
Total Liver ◽  
Liver Copper

The degradation of purified 35S-labelled rat liver isometallothioneins (MT) by lysosomal extracts was studied. Zn-MT-I was more readily hydrolysed than Zn-MT-II, but no significant degradation of the Cu-containing metallothioneins could be detected, even after 24 h incubation. The susceptibility of MT to degradation in vitro may be related to the strength of the metal-thiolate bonds. However, the turnover rates of cytosolic MT in vivo, as established by pulse-labelling techniques, are apparently subject to different controls. The half-lives of MT-I and -II in the liver cytosol of Cu2+-injected rats were only 15.4 +/- 1.5 and 18.2 +/- 1.1 h respectively. Approx. 25% of the total liver MT was present in particulate fractions (probably in lysosomes) of the liver and had a half-life of 25.1 +/- 4.1 h.

Sign in / Sign up

Export Citation Format

Share Document