scholarly journals ISOLATION AND PROPERTIES OF LIVER CELL NUCLEOLI

1956 ◽  
Vol 2 (2) ◽  
pp. 127-145 ◽  
Author(s):  
K. J. Monty ◽  
M. Litt ◽  
E. R. M. Kay ◽  
A. L. Dounce
Keyword(s):  
Liver Cell ◽  
Cell Type ◽  
Isolated Nuclei ◽  
Dna And Rna ◽  
Detailed Method ◽  
Liver Nuclei ◽  
Specific Activities ◽  
New Hypothesis ◽  
Isolated Liver ◽  
Isolated Rat

1. The significance of the term nucleolus has been discussed. 2. A detailed method for the isolation of nucleoli from already isolated rat or cat liver nuclei has been presented. 3. The presence of DNA in isolated liver cell nucleoli has been indicated by histochemical methods. 4. The percentages of DNA and RNA in the isolated nucleoli have been determined by chemical analysis. 5. The specific activities of aldolase, arginase, and catalase have been determined for two subnuclear fractions and for the isolated nucleoli of rat and cat liver, and the relative amounts of these enzymes in the same subnuclear fractions and nucleoli of rat liver have been measured. 6. The significance of the above findings has been discussed and consideration has been given to what types of isolated nuclei might best serve as starting material for the isolation of nucleoli. 7. A new hypothesis has been presented that nucleoli of the liver cell type may function primarily in furnishing (directly or indirectly) templates for the synthesis of the particular enzymes that must govern the chemistry of mitosis.

scholarly journals Decreased ribonucleic acid synthesis in isolated rat liver nuclei during starvation

1970 ◽  
Vol 120 (2) ◽  
pp. 381-384 ◽  
Author(s):  
D. Rickwood ◽  
H. G. Klemperer
Keyword(s):  
Rna Polymerase ◽  
Ammonium Sulphate ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Isolated Nuclei ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat

1. Isolated nuclei from starved rats showed a lowered incorporation of [14C]UMP into RNA. 2. The Mg2+-dependent incorporation was decreased by 30% after 1 day of starvation, but incorporation in the presence of Mn2+ and ammonium sulphate decreased only after longer periods of starvation. 3. RNA synthesis by nuclei in the presence of excess of added RNA polymerase was unchanged after 1 day of starvation and was inhibited by 20% after 4 days. 4. The capacity of nuclei to bind actinomycin D was unchanged after 1 day and was decreased by 20% after 4 days of starvation.

scholarly journals The effects of copper and other ions on the ribonucleic acid polymerase activity of isolated rat liver nuclei

1969 ◽  
Vol 111 (1) ◽  
pp. 115-119 ◽  
Author(s):  
F. Novello ◽  
F. Stirpe
Keyword(s):  
Rna Polymerase ◽  
Ammonium Sulphate ◽  
Rat Liver ◽  
Ribonucleic Acid ◽  
Polymerase Activity ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Liver ◽  
Isolated Rat

1. The effects of various ions on the Mg2+- and Mn2+/ammonium sulphate-activated RNA polymerase activities of isolated liver nuclei were studied. 2. The Mg2+-activated RNA polymerase reaction was inhibited by more than 60% by Cd2+, SeO32−, Be2+, Cu2+, Co2+, Ca2+ and La3+, all at 1mm concentrations. 3. The Mn2+/ammonium sulphate-activated RNA polymerase reaction was strongly inhibited by Hg2+, Cd2+, Cu2+ and Ag+. The effect of Hg2+, Cd2+ and Ag+ was relieved by cysteine or mercaptoethanol. 4. Inhibition by Cu2+ was not affected by addition of DNA, and was relieved only partially by EDTA or histidine. 5. No changes of RNA polymerase activities were observed in nuclei isolated from the liver of rats treated with copper albuminate.

scholarly journals Influence of nucleotides, cations and nucleoside triphosphatase inhibitors on the release of ribonucleic acid from isolated rat liver nuclei

1980 ◽  
Vol 188 (1) ◽  
pp. 91-97 ◽  
Author(s):  
P S Agutter
Keyword(s):  
Rat Liver ◽  
Incubation Medium ◽  
Significant Extent ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Dna And Rna ◽  
Nuclear Stability ◽  
Liver Nuclei ◽  
Isolated Rat ◽  
Nucleoside Triphosphatase

The reasons underlying reported discrepancies in the effects of ATP, ADP, adenosine 5′-[beta gamma-methylene]triphosphate, AMP + PPi, P-chloromercuribenzoate and F- on RNA efflux from isolated rat liver nuclei and on nuclear envelope nucleoside triphosphatase activity were investigated. The stimulatory effect of ADP was attributed to myokinase activity associated with the nuclei; this activity was eluted on repeated washing with nuclear incubation medium. In the absence of Ca2+ and Mn2+, ATP, adenosine 5′[beta gamma-methylene]triphosphate and AMP +PPi were found to promote release of both DNA and RNA. In the presence of 0.5 mM-Ca2+ and 9.3 mM-Mn2+, only ATP promoted RNA efflux to a significant extent. In the absence of spermidine, Ca2+ and Mn2+, nuclei released large quantities of DNA and RNA into the medium; this effect was promoted by p-chloromereuribenzoate. In the presence of the three cations, however, p-chloromercuribenzoate inhibited RNA efflux. F- caused a slight leakage of DNA from nuclei. The results are discussed in terms of models for the effects of ATP and analogues on RNA efflux and nuclear stability.

scholarly journals Modulation by Exogenous Histones of Phosphorylation of Non-Histone Nuclear Proteins in Isolated Rat Liver Nuclei

1973 ◽  
Vol 248 (21) ◽  
pp. 7595-7600
Author(s):  
Edward M. Johnson ◽  
Giorgio Vidali ◽  
Virginia C. Littau ◽  
Vincent G. Allfrey
Keyword(s):  
Rat Liver ◽  
Nuclear Proteins ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat

Structural and biochemical aspects of liver cell nuclear organization in normal and scalded rats

1984 ◽  
Vol 71 (1) ◽  
pp. 75-93
Author(s):  
L. Sevaljevic ◽  
M. Petrovic ◽  
G. Poznanovic ◽  
A. Skaro ◽  
D. Pantelic
Keyword(s):  
Nuclear Structure ◽  
Thermal Injury ◽  
Nuclear Organization ◽  
Chromatin Condensation ◽  
Metal Chelators ◽  
Nuclear Pores ◽  
Dna And Rna ◽  
Liver Nuclei ◽  
Minimal Residual

The response of rat liver nuclei to thermal injury was studied at the ultrastructural and biochemical levels using nuclei isolated in the presence of either Mg2+ or polyamines and metal chelators. The extent of chromatin condensation, as revealed by electron microscopy, increased in the order: nuclei in situ, Mg-stabilized nuclei, polyamine-stabilized nuclei. In addition, we observed that thermal injury caused an increase in the number of nuclear pores, an enlargement of nucleoli and an accumulation of ribonucleoprotein material. Along with this, greater amounts of protein, DNA and RNA were retained in nuclei from scalded rats. The salt-resistant residue from Mg-stabilized nuclei was a spherical proteinaceous structure of the nuclear matrix, whereas that of the polyamine-stabilized nuclei was amorphous and deprived of three major constituents of the spherical matrix, the 60–70 X 10(3) Mr lamina proteins. However, exposure of the polyamine-stabilized nuclei to Ca2+ and Mg2+ rendered the 60–70 X 10(3) Mr proteins salt-insoluble and thus enabled the extraction of a spherical residual nuclear structure. This structure was highly enriched in DNA, RNA and non-histone proteins and, hence, more like dehistonized nuclei than the minimal residual nuclear structure. It retained 70% of DNA in the controls but virtually all the DNA in scalded rats. This difference was interpreted to reflect activation-related changes in chromatin organization.

scholarly journals Cytochemical studies on the relation of nucleoside triphosphatase activity to ribonucleoproteins in isolated rat liver nuclei.

1980 ◽  
Vol 28 (1) ◽  
pp. 27-35 ◽  
Author(s):  
A Vorbrodt ◽  
G G Maul
Keyword(s):  
Nuclear Envelope ◽  
Rat Liver ◽  
Enzyme Reaction ◽  
Point Of View ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat

Cytochemical tests for nucleosidetriphosphatase (NTPase) and Bernhard's preferential staining for ribonucleoproteins (RNP) were applied to isolated rat liver nuclei. The strongest and most easily reproducible positive reaction for NTPase was detected at pH 7.7 with ATP and GTP. This reaction was activated by Mg2+ and Ca2+ and inhibited by Be2+, Zn2+, quercetin, and ribonuclease. The major sites of enzyme reaction were intranuclear RNA-containing structures. Incubation of nuclei in ATP-stimulated RNA-release medium eliminated a considerable part of the material showing both NTPase reaction and staining for RNP; the perichromatin granules disappeared, while interchromatin granules remained. NTPase activity in the nuclear envelope seems to be associated with the annular part of nuclear pore complexes (permanent component) and with RNP particles translocated through nuclear pores or attached to the surface of nuclei (transitional component). From a morphological point of view, these observations support previous biochemical data suggesting the existence of a connection between NTPase activity and the translocation of RNP particles through the nuclear envelope.

scholarly journals CYTOFLUOROMETRIC DETERMINATION OF LYSINE WITH DANSYLCHLORIDE

1968 ◽  
Vol 16 (7) ◽  
pp. 459-466 ◽  
Author(s):  
A. ROSSELET ◽  
F. RUCH
Keyword(s):  
Rat Liver ◽  
Lysine Content ◽  
Amino Groups ◽  
Isolated Rat Liver ◽  
Model Experiments ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat

Dansylchloride (l-dimethylamino-naphthalene-5-sulfochloride) may be used for cytofluorometric determination of lysine. By means of model experiments on protein smears it is shown that the reaction must be carried out in ethanol if it is to be specific for amino groups. The fluorescence given by isolated rat liver nuclei treated with dansylchloride corresponds to the three classes of 2n, 4n and 8n nuclei. The dansylfluorescence of several kinds of sperms is proportional to their lysine content. In rat liver nuclei, 95% of the lysine is dansylated and the lysine content may be determined in absolute values by comparison with polylysine. In spermatozoa only 50% of the lysine reacts.

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