scholarly journals STUDIES ON ISOLATED NUCLEI

1963 ◽  
Vol 18 (2) ◽  
pp. 267-291 ◽  
Author(s):  
Rachele Maggio ◽  
Philip Siekevitz ◽  
George E. Palade
Keyword(s):  
Nuclear Envelope ◽  
Base Composition ◽  
Nuclear Fraction ◽  
Pig Liver ◽  
Lower Phase ◽  
Dna Recovery ◽  
Isolated Nuclei ◽  
Nuclear Rna ◽  
Electron Microscopical ◽  
Guinea Pig Liver

This article describes a method for the isolation of nuclei from guinea pig liver. It involves the homogenization of the tissue in 0.88 M sucrose-1.5 mM CaCl2 followed by centrifugation in a discontinuous density gradient in which the upper phase is the homogenate and the lower phase is 2.2 M sucrose-0.5 mM CaCl2. Based on DNA recovery, the isolated fraction contains 25 to 30 per cent of the nuclei of the original homogenate. Electron microscopical observations showed that ∼88 per cent of the isolated nuclei come from liver cells (the rest from von Kupffer cells and leucocytes) and that ∼90 per cent of the nuclei appear intact, with well preserved nucleoli, nucleoplasm, nuclear envelope, and pores. Cytoplasmic contamination is minimal and consists primarily of the nuclear envelope and its attached ribosomes. The nuclear fraction consists of ∼22.3 per cent DNA, ∼4.7 per cent RNA, and ∼73 per cent protein, the DNA/RNA ratio being 4.7. Data on RNA extractibility by phosphate and salt and on the base composition of total nuclear RNA are included.

scholarly journals ISOLATION AND BIOCHEMICAL CHARACTERIZATION OF NUCLEI FROM CHICK EMBRYO LIVER

1971 ◽  
Vol 50 (2) ◽  
pp. 385-398 ◽  
Author(s):  
Genevieve S. Incefy ◽  
Attallah Kappas
Keyword(s):  
Electron Microscope ◽  
Chick Embryo ◽  
Rna Polymerase ◽  
Biochemical Characterization ◽  
Nuclear Fraction ◽  
Dna Recovery ◽  
Isolated Nuclei ◽  
Sucrose Solutions ◽  
Embryo Liver

A procedure is described for the isolation of enzymatically active nuclei from chick embryo liver. It consists of the homogenization of the pooled tissue in 0.32 M sucrose-3 mM MgCl2 followed by a slow centrifugation. The resulting nuclear pellet is then purified further in a discontinuous density gradient composed of sucrose solutions containing Mg2+ ions, the lower portion of the gradient being 2.2 M sucrose-1 mM MgCl2. Based on DNA recovery, the nuclear fraction isolated by the procedure described contained an average of 62% of the nuclei in the original filtered homogenate. Light and electron microscope examinations showed that 90% of the isolated nuclei were derived from hepatocytes. They appeared intact with well preserved nucleoplasmic and nucleolar components, nuclear envelope, and pores. The isolated nuclei were quite pure, having a very low level of cytoplasmic contamination as indicated by cytoplasmic enzyme marker activities and electron microscope studies. The nuclear fraction consisted of 19.9% DNA, 6.2% RNA, 74% protein, the average RNA/DNA ratio being 0.32. Biosynthetic activities of the two nuclear enzymes NAD-pyrophosphorylase and DNA-dependent RNA polymerase were preserved. The specific activities of these enzymes were: NAD-pyrophosphorylase, 0.049 µmoles nicotinamide adenine dinucleotide (NAD) synthesized/min per mg protein; Mg2+ activated RNA polymerase, 4.3 µµmoles UMP-2-C14 incorporated into RNA/µg DNA per 10 min; and Mn2+-(NH4)2SO4 activated RNA-polymerase, 136 µµmoles UMP-2-C14 incorporated into RNA/µg DNA per 45 min.

scholarly journals STUDIES ON ISOLATED NUCLEI

1963 ◽  
Vol 18 (2) ◽  
pp. 293-312 ◽  
Author(s):  
Rachele Maggio ◽  
Philip Siekevitz ◽  
George E. Palade
Keyword(s):  
Nucleotide Composition ◽  
Gradient System ◽  
Variable Amount ◽  
Cell Nuclei ◽  
Pig Liver ◽  
Isolated Nuclei ◽  
Guinea Pig Liver ◽  
Rna And Dna ◽  
Degree Of Fragmentation

This paper describes the subfractionation of nuclei isolated from guinea pig liver by the procedure presented in the first article of the series (8). Centrifugation in a density gradient system of nuclear fractions disrupted by sonication permits the isolation of the following subfractions: (a) a nucleolar subfraction which consists mainly of nucleoli surrounded by a variable amount of nucleolus-associated chromatin and contaminated by chromatin blocks derived primarily from von Kupffer cell nuclei; (b) and (c), two nucleoplasmic subfractions (I and II) which consist mainly of chromatin threads in a coarser (I) or finer (II) degree of fragmentation. The protein, RNA, and DNA content of these subfractions was determined, and their RNA's characterized in terms of NaCl-solubility, nucleotide composition, and in vivo nucleotide turnover, using inorganic 32P as a marker. The results indicate that there are at least three types of RNA in the nucleus (one in the nucleolus and two in the nucleoplasm or chromatin), which differ from one another in NaCl-solubility, nucleotide composition, turnover, and possibly sequence. Possible relations among these RNA's and those of the cytoplasm are discussed.

Die Bedeutung der Homogenisationsart und -intensität für die Größe und Konstanz der Sauerstoffaufnahme von Meerschweinchen-Leberhomogenat / The Influence of Mode and Intensity of Homogenization on the Absolute Value and Stability of Oxygen Consumption of Guinea Pig Liver Homogenates

1977 ◽  
Vol 32 (11-12) ◽  
pp. 908-912 ◽  
Author(s):  
H. J. Schmidt ◽  
U. Schaum ◽  
J. P. Pichotka
Keyword(s):  
Oxygen Uptake ◽  
Guinea Pig ◽  
Measuring Time ◽  
Pig Liver ◽  
Absolute Value ◽  
Modified Method ◽  
Simultaneous Measurements ◽  
Liver Homogenates ◽  
The Absolute ◽  
Guinea Pig Liver

Abstract The influence of five different methods of homogenisation (1. The method according to Potter and Elvehjem, 2. A modification of this method called Potter S, 3. The method of Dounce, 4. Homogenisation by hypersonic waves and 5. Coarce-grained homogenisation with the “Mikro-fleischwolf”) on the absolute value and stability of oxygen uptake of guinea pig liver homogenates has been investigated in simultaneous measurements. All homogenates showed a characteristic fall of oxygen uptake during measuring time (3 hours). The modified method according to Potter and Elvehjem called Potter S showed reproducible results without any influence by homogenisation intensity.

Precision-cut Guinea-pig Liver Slices as a Tool for Studying the Toxicity of Volatile Anaesthetics

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 191-199
Author(s):  
Hanan N. Ghantous ◽  
Jeanne Fernando ◽  
Scott E. Morgan ◽  
A. Jay Gandolfi ◽  
Klaus Brandel
Keyword(s):  
Guinea Pig ◽  
Rank Order ◽  
Normal Liver ◽  
Liver Slice ◽  
Volatile Anaesthetics ◽  
Pig Liver ◽  
Liver Slices ◽  
Guinea Pig Liver ◽  
Krebs Henseleit Buffer

Cultured precision-cut liver slices retain normal liver architecture and physiological biochemical functions. Hartley male guinea-pig liver slices have proven to be a good model for studying the biotransformation and toxicity of halothane. This system was used to evaluate the biotransformation and toxicity of different volatile anaesthetics (halothane, enflurane, isoflurane and sevoflurane), and compare their effects to those of new anaesthetics (desflurane). Liver slices (250–300μm thick) were incubated in sealed roller vials, containing Krebs Henseleit buffer at 37°C under 95% O2:5% CO2 atmosphere. Volatile anaesthetics were delivered by volatilisation after pre-incubation for 1 hour to produce a constant concentration in the medium. Production of the metabolites, trifluroacetic acid and fluoride ion, was measured. Intracellular potassium ion content, protein synthesis and secretion were determined as indicators of viability of the slices. The rank order of biotransformation of anaesthetics by the liver slices was halothane >sevoflurane>isoflurane and enflurane>desflurane. The rank order of hepatotoxicity of these anaesthetics was halothane>isoflurane and enflurane>sevoflurane and desflurane. Halothane is the anaesthetic which is metabolised furthest and has the most toxic effect, while desflurane is the least metabolised anaesthetic and has the least toxicity. This in vitro cultured precision-cut liver slice system appears to be suitable for studying the biotransformation of volatile anaesthetics and correlating its role in the resulting toxicity.

scholarly journals Exolytic hydrolysis of toxic plant glucosides by guinea pig liver cytosolic beta-glucosidase.

1992 ◽  
Vol 267 (20) ◽  
pp. 14027-14032
Author(s):  
V Gopalan ◽  
A Pastuszyn ◽  
W R Galey ◽  
R.H. Glew
Keyword(s):  
Guinea Pig ◽  
Pig Liver ◽  
Beta Glucosidase ◽  
Toxic Plant ◽  
Hydrolysis Of ◽  
Guinea Pig Liver

scholarly journals THE REDUCTION OF l-XYLULOSE TO XYLITOL BY GUINEA PIG LIVER MITOCHONDRIA

1956 ◽  
Vol 221 (2) ◽  
pp. 697-709 ◽  
Author(s):  
Oscar Touster ◽  
V.H. Reynolds ◽  
Ruth M. Hutcheson
Keyword(s):  
Guinea Pig ◽  
Liver Mitochondria ◽  
Pig Liver ◽  
Guinea Pig Liver
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