scholarly journals AUTORADIOGRAPHIC ANALYSIS ON AGAR PLATES OF ANTIGENS FROM SUB CELLULAR FRACTIONS OF RAT LIVER SLICES

1961 ◽  
Vol 10 (3) ◽  
pp. 411-423 ◽  
Author(s):  
W. S. Morgan ◽  
P. Perlmann ◽  
T. Hultin
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Serum Proteins ◽  
Free Cell ◽  
Radioactive Material ◽  
Rat Serum ◽  
Agar Diffusion ◽  
Liver Slices ◽  
Ionic Detergent ◽  
Typical Cell

Slices of rat livers were incubated with 14C amino acids, homogenized, and subjected to differential centrifugation. The microsomes were further extracted with the non-ionic detergent Lubrol W and with EDTA. These extracts and the microsome free "cell sap," freed from the pH 5 precipitable fraction, were subsequently reacted with antisera using agar diffusion techniques. The antisera employed were obtained from rabbits injected with different subcellular fractions of rat liver or with rat serum proteins. When the agar diffusion plates were autoradiographed it was found that some of the precipitates were radioactive while others were not. Control experiments indicated that this labeling was due to the specific incorporation of 14C amino acids into various rat liver antigens during incubation of the slices rather than to a non-specific adsorption of radioactive material to the immunological precipitates. When the slices were incubated with the isotope for up to 30 minutes, the serum proteins which could be extracted from the microsomes with the detergent were strongly labeled, as were a number of additional microsomal antigens of unknown significance. In contrast, the serum proteins present in the cell sap were only weakly labeled. Most of the typical cell sap proteins, both those precipitable and those soluble at pH 5, seemed to remain unlabeled. No consistently reproducible results were obtained with the EDTA extracts of the ribosomal residues remaining after extraction of the microsomes with the detergent. Incubation of the liver slices for longer periods (up to 120 minutes) led to a strong labeling of the serum proteins in the cell sap as well as to the appearance of labeling in additional cell sap proteins. The results are discussed with regard to the subcellular site of synthesis and the metabolism of the different antigens.

EFFECTS OF HYPOGLYCIN A ON THE METABOLISM OF AMINO ACIDS BY LIVER SLICES

1964 ◽  
Vol 42 (1) ◽  
pp. 139-142 ◽  
Author(s):  
S. J. Patrick ◽  
L. C. Stewart
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Inhibitory Effects ◽  
Liver Slices

The effects of hypoglycin A on the metabolism of L-leucine-C14, L-alanine-C14, and L-glutamic-acid-C14 by rat liver slices have been investigated. Hypoglycin exerted markedly inhibitory effects on the conversion of leucine-C14 to fatty acid, cholesterol, and CO2. Conversion of alanine-C14 and glutamic acid-C14 to fatty acids was also inhibited by hypoglycin. No effects of hypoglycin on the conversion of C14-amino acids into protein or glycogen were demonstrated.

scholarly journals LABELING WITH 14C AMINO ACIDS OF ALBUMIN-LIKE PROTEIN BY RAT LIVER RIBONUCLEOPROTEIN PARTICLES

1963 ◽  
Vol 16 (3) ◽  
pp. 471-481 ◽  
Author(s):  
Alexandra von der Decken
Keyword(s):  
Amino Acids ◽  
Serum Albumin ◽  
Cellulose Acetate ◽  
Electrophoretic Mobility ◽  
Rat Liver ◽  
Deae Cellulose ◽  
Rat Liver Microsomes ◽  
Rat Serum ◽  
Ribonucleoprotein Particles ◽  
Rat Serum Albumin

Ribonucleoprotein particles were prepared by treatment of rat liver microsomes with detergents and high concentrations of KCl. They were active in incorporating 14C amino acids into protein when incubated with cell sap together with ATP, GTP, and a system to regenerate the triphosphates. The albumin of the incubation mixture, soluble at 105,000 g, and that of the fraction released by ultrasonication of the particles were studied by immunoelectrophoresis in agar gel. When the ribonucleoprotein particles were incubated with cell sap the immunological precipitation lines formed with antiserum to rat serum albumin were highly radioactive as tested by autoradiography. After zone electrophoresis on cellulose acetate, two immunologically reactive albumins were obtained which differed in their electrophoretic mobility from rat serum albumin. Labeled albumin, when purified on DEAE-cellulose columns, retained its radioactivity as tested by autoradiography following immunoelectrophoresis. On cellulose acetate this purified albumin showed an electrophoretic mobility higher than that of rat serum albumin.

scholarly journals The Influence of Amino Acids on Copper Uptake by Rat Liver Slices *

1967 ◽  
Vol 46 (4) ◽  
pp. 659-667 ◽  
Author(s):  
Daisy I. M. Harris ◽  
Andrew Sass-Kortsak
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Copper Uptake ◽  
Liver Slices

scholarly journals The effect of actinomycin D on the synthesis of ribonucleic acid and protein in rat liver parenchymal cells in suspension and liver slices

1968 ◽  
Vol 108 (5) ◽  
pp. 741-748 ◽  
Author(s):  
G. Shanmugam ◽  
P. M. Bhargava
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Tissue Slices ◽  
Liver Parenchymal ◽  
Average Ratio ◽  
Cellular Volume ◽  
Liver Slices ◽  
Parenchymal Cells

1. Rat liver parenchymal cells in suspension are shown to require a higher concentration of actinomycin D than liver slices for equivalent inhibition of the incorporation of [14C]adenine, [14C]uracil and [32P]phosphate into RNA, and of 14C-labelled amino acids into protein; protein synthesis is much less susceptible to actinomycin D inhibition than RNA synthesis in both the tissue preparations. Possible causes for these differences are discussed. 2. The uptake of [3H]actinomycin D in the first few minutes was much greater in the cell suspensions than in the tissue slices; that in the next 1–4hr. was about the same in both the cases. The uptake by both the tissue preparations was at all times proportional to the concentration of the drug within the range 0·5–2·0μg./ml. 3. In the slices actinomycin D taken up initially was concentrated almost exclusively in the nuclei; with time the concentration of the drug in the mitochondria and the supernatant increased more rapidly than in the nuclei though at no stage did it exceed that in the nuclei. In the cell suspension the largest concentration of the drug taken up initially was found in the supernatant; most of the drug taken up subsequently also stayed in the supernatant. 4. When the drug concentration in the incubation medium was 1μg./ml., its concentration within the parenchymal cells in suspension and the parenchymal cells in the slices reached 2·2 and 1·6μg./cm.3 of cellular volume respectively. On average, 7% of the drug was removed from the medium by the cells in suspension and 23% by the cells in the slices; the average ratio of intracellular to extracellular concentration was 2·4 in the former and 2·1 in the latter case.

Studies on Acute Phase Proteins of Rat Serum. V. Effect of Induced Inflammation on the Synthesis of Albumin and α1-Acid Glycoprotein by Liver Slices

1975 ◽  
Vol 53 (4) ◽  
pp. 401-414 ◽  
Author(s):  
J. C. Jamieson ◽  
K. E. Morrison ◽  
D. Molasky ◽  
B. Turchen
Keyword(s):  
Acute Phase ◽  
Polypeptide Chain ◽  
Serum Proteins ◽  
Acute Phase Proteins ◽  
Rat Serum ◽  
Acid Glycoprotein ◽  
Liver Slices ◽  
Microsome Fraction ◽  
Lower Capacity ◽  
Acute Phase Serum

Liver slices from normal rats and those suffering from inflammation for 24–48 h were incubated with L-[14C]leucine or D-[I4C]glucosamine. Immunological techniques coupled with radioautography indicated that the microsome fraction prepared from slices contained the subcellular site of synthesis of the polypeptide chain of serum albumin, and the polypeptide and carbohydrate chains of α1-acid glycoprotein; both proteins were also present in the medium in labelled forms. The contents of albumin and α1-acid glycoprotein in the medium and in extracts of liver from experiments with liver slices from control rats and 8–72 h experimental rats were determined using the quantitative precipitin technique. There was a net increase in synthesis of both proteins when slices from control and experimental animals were used, the increase showing up in medium proteins. However, slices from livers from 8–72 h experimental rats had a greater capacity for synthesis of α1-acid glycoprotein and a lower capacity for synthesis of albumin than slices from livers from control rats, the greatest changes occurring with slices from 24 h experimental rats. Changes in synthetic capacities of liver slices from experimental rats for albumin and α1-acid glycoprotein were always accompanied by large increases in specific radioactivities of total medium proteins when experiments involved incubation of slices with L-[3H]leucine and D-[14C]glucosamine. It is suggested that the increase in specific radioactivities of medium proteins following incubation of liver slices from experimental rats with labelled leucine and glucosamine is a characteristic of the response of liver to inflammation, and reflects changes in the capacity of liver for the synthesis of α1-acid glycoprotein and other acute phase serum proteins.

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