scholarly journals The fractionation of nuclei from mammalian cells by zonal centrifugation

1968 ◽  
Vol 109 (1) ◽  
pp. 127-135 ◽  
Author(s):  
I R Johnston ◽  
A P Mathias ◽  
F. Pennington ◽  
D. Ridge
Keyword(s):  
Rat Liver ◽  
Mammalian Cells ◽  
Mouse Liver ◽  
The Other ◽  
Slow Speed ◽  
Adult Rats ◽  
Sucrose Solutions ◽  
Liver Nuclei ◽  
Effect Of Age ◽  
Zonal Rotor

1. Purified liver nuclei from adult rats separate into two main zones when centrifuged in the slow-speed zonal rotor. One zone contains diploid nuclei, the other tetraploid. 2. The effect of age on the pattern of rat liver ploidy was examined. Tetraploid nuclei are virtually absent from young animals. They increase in proportion steadily with age. Partial hepatectomy disturbs the pattern of ploidy. 3. The zonal centrifuge permits the separation of diploid, tetraploid, octaploid and hexadecaploid nuclei from mouse liver. 4. Rat liver nuclei are isopycnic with sucrose solutions of density 1·35 at 5°.

STUDY OF SOME FACTORS THAT AFFECT THE DISTRIBUTION OF NUCLEAR VOLUMES IN PREPARATIONS OF RAT LIVER NUCLEI

1967 ◽  
Vol 45 (7) ◽  
pp. 1175-1183 ◽  
Author(s):  
Roberto Umaña
Keyword(s):  
Rat Liver ◽  
Dna Content ◽  
Direct Relationship ◽  
Magnesium Ion ◽  
Homogenization Procedure ◽  
Ion Concentrations ◽  
Ph Values ◽  
Sucrose Solutions ◽  
Liver Nuclei ◽  
Calcium And Magnesium

The effect of the homogenization procedure, the centrifugation scheme, and the composition of the suspension medium on the distribution of nuclear volumes has been studied.It has been shown that the Waring Blendor not only destroys a greater number of the nuclei during homogenization, but also that this destruction is a selective one. At neutral pH values, no direct relationship appears to exist between the DNA content of the nuclei and their density. For this reason, purification in concentrated sucrose solutions produces a selective loss of the lighter nuclei, which includes small diploid stromal nuclei and some of the larger polyploid type of parenchymal nuclei.The study of the effect of increasing the calcium and magnesium ion concentrations (from 0.001 to 0.005 M) on the nuclear distribution showed that these ions produce a selective shrinkage and condensation of the nuclei, probably through different mechanisms.

Katabole Eigenschaften 5',5"-verknüpfter Dinucleosidphosphate in Nuclei aus Rattenleber / Catabolic Properties of 5',5"-Linked Dinucleosidephosphates in Rat Liver Nuclei

1982 ◽  
Vol 37 (9) ◽  
pp. 818-823 ◽  
Author(s):  
Siegmar Bornemann ◽  
Eckhard Schlimme
Keyword(s):  
Rat Liver ◽  
Enzymatic Degradation ◽  
The Other ◽  
Rat Liver Nuclei ◽  
Liver Nuclei

We report on the enzymatic degradation of 14C-labelled 5',5"-linked dinucleoside triphosphates Gp3A, 2-O-mGp3A, 2'dGp3A, 2',3"ddGp3A and m7Gp3A in rat liver nuclei. The 2'-desoxy- and 2',3'-didesoxy compounds are poorer substrates than the other cap-structured dinucleotides in­vestigated.

scholarly journals Activity of nicotinamide–adenine dinucleotide pyrophosphorylase in liver nuclei. Effects of partial hepatectomy, hepatotoxins and dietary changes

1968 ◽  
Vol 108 (1) ◽  
pp. 89-93
Author(s):  
F. Stirpe ◽  
E. Della Corte
Keyword(s):  
Enzyme Activity ◽  
Partial Hepatectomy ◽  
Rat Liver ◽  
Nicotinamide Adenine Dinucleotide ◽  
Mouse Liver ◽  
Actinomycin D ◽  
Newborn Rats ◽  
Dietary Changes ◽  
Liver Nuclei ◽  
Protein Free Diet

1. The activity of NAD pyrophosphorylase is lower in nuclei isolated from regenerating rat liver than in normal nuclei, and this is due to leakage of the enzyme from the nuclei during the isolation. 2. The NAD pyrophosphorylase activity is lower in liver nuclei from newborn rats, and from rats on a protein-free diet, but no leakage occurs in these cases. 3. Poisoning with α-amanitin brings about a transient enhancement of NAD pyrophosphorylase activity in mouse liver nuclei. 4. No changes of enzyme activity were observed after 72hr. starvation, administration of actinomycin D or infection with MHV3 virus.

scholarly journals Guanine deaminase in rat liver and mouse liver and brain

1972 ◽  
Vol 128 (5) ◽  
pp. 1079-1088 ◽  
Author(s):  
K. S Kumar ◽  
A. Sitaramayya ◽  
P. S. Krishnan
Keyword(s):  
Rat Brain ◽  
Rat Liver ◽  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Mouse Liver ◽  
Deae Cellulose ◽  
The Other ◽  
Guanine Deaminase ◽  
Sigmoidal Kinetics ◽  
Km Value

1. The guanine deaminase in rat liver supernatant preparations was resolved into two fractions, A and B, on DEAE-cellulose columns. The two differed in electrophoretic mobility and in various properties. The most noteworthy distinction between A and B components was that the enzyme A activity showed a sigmoid dependence on substrate concentration whereas the enzyme B showed classical Michaelis–Menten kinetics. The Km value of enzyme A for guanine was 5.3μm and that of enzyme B 20μm. 2. The entire guanine deaminase activity of mouse liver was contained in the 15000g supernatant of iso-osmotic homogenates. 3. A reinvestigation of the behaviour of rat brain 15000g supernatant guanine deaminase isoenzymes revealed that one enzyme had sigmoidal kinetics and the other enzyme showed a hyperbolic response. 4. Of the guanine deaminase in mouse brain iso-osmotic sucrose homogenate 80% was recovered in the 15000g supernatant and the rest from the particles. The supernatant guanine deaminase was resolvable into two fractions on DEAE-cellulose columns. One enzyme showed sigmoidal kinetics whereas the other showed a hyperbolic response to increasing substrate concentration; the Km values for the reaction with guanine were respectively 5 and 66μm. 5. The particulate fractions of mouse liver and brain were devoid of any overt inhibitory activity.

Effect of 5′-Terminated (2′— 5′)-01igoadenylates on Cap Degrading Activities in Rat Liver Nuclei

1983 ◽  
Vol 38 (7-8) ◽  
pp. 631-634 ◽  
Author(s):  
Winfried Michels ◽  
Eckhard Schlimme
Keyword(s):  
Synergistic Effect ◽  
Rat Liver ◽  
Cellular Metabolism ◽  
The Other ◽  
Rat Liver Nuclei ◽  
Other Hand ◽  
Infected Cells ◽  
Liver Nuclei ◽  
Exonucleolytic Degradation

(2'-5')-oligoadenylates bearing a 5'-terminal triphosphate or a 5'GTP-group inhibit the activity of a dinucleoside triphosphatase in rat liver nuclei thereby protecting mRNA against 5'-exonucleolytic degradation. (2'-5')-oligoadenylates, on the other hand, were known to enhance the activity of an endoribonuclease, RNaseF. Thus a synergistic effect may be assumed in vivo, i.e. cellular metabolism seems to be protected twice in virus-infected cells.

Ultrastructural localization of specific nucleoprotein fractions

1978 ◽  
Vol 36 (2) ◽  
pp. 204-205
Author(s):  
G. L. Brown
Keyword(s):  
Gel Electrophoresis ◽  
Mouse Liver ◽  
Polyacrylamide Gel Electrophoresis ◽  
Ultrastructural Localization ◽  
Polyacrylamide Gel ◽  
Acid Extraction ◽  
Acid Solutions ◽  
Low Salt ◽  
Liver Nuclei ◽  
Phosphate Groups

Bismuth (Bi) stains nucleoproteins (NPs) by interacting with available amino and primary phosphate groups. These two staining mechanisms are distinguishable by glutaraldehyde crosslinking (Fig. 1,2).Isolated mouse liver nuclei, extracted with salt and acid solutions, fixed in either formaldehyde (form.) or gl utaraldehyde (glut.) and stained with Bi, were viewed to determine the effect of the extractions on Bi stainina. Solubilized NPs were analyzed by SDS-polyacrylamide gel electrophoresis.Extraction with 0.14 M salt does not change the Bi staining characteristics (Fig. 3). 0.34 M salt reduces nucleolar (Nu) staining but has no effect on interchromatinic (IC) staining (Fig. 4). Proteins responsible for Nu and glut.- insensitive IC staining are removed when nuclei are extracted with 0.6 M salt (Fig. 5, 6). Low salt and acid extraction prevents Bi-Nu staining but has no effect on IC staining (Fig. 7). When nuclei are extracted with 0.6 M salt followed by low salt and acid, all Bi-staining components are removed (Fig. 8).

Further Studies on the Ultrastructure of Harderian Gland in Adult Rats

1974 ◽  
Vol 32 ◽  
pp. 288-289
Author(s):  
Alfredo Feria-Velasco ◽  
Guadalupe Tapia-Arizmendi
Keyword(s):  
Fine Structure ◽  
Domestic Fowl ◽  
Animal Species ◽  
Acinar Cells ◽  
Harderian Gland ◽  
Myoepithelial Cells ◽  
The Other ◽  
Albino Rats ◽  
Adult Rats ◽  
Cell Components

The fine structure of the Harderian gland has been described in some animal species (hamster, rabbit, mouse, domestic fowl and albino rats). There are only two reports in the literature dealing on the ultrastructure of rat Harderian gland in adult animals. In one of them the author describes the myoepithelial cells in methacrylate-embbeded tissue, and the other deals with the maturation of the acinar cells and the formation of the secretory droplets. The aim of the present work is to analize the relationships among the acinar cell components and to describe the two types of cells located at the perifery of the acini.

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