Increased RNA synthesis in nuclei isolated from rat liver tissue slices incubated with cyclic adenosine 3′,5′-monophosphate or glucagon

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.

Download Full-text

The Relationship of the Aflatoxin in the Diet on Rat Liver Tissue

Journal of University of Shanghai for Science and Technology ◽

10.51201/jusst12652 ◽

2021 ◽

Vol 23 (2) ◽

Author(s):

Dr. Saba Thamer Mosa ◽

Keyword(s):

Immune System ◽

Rat Liver ◽

Aflatoxin B1 ◽

Liver Tissue ◽

Rna Synthesis ◽

Animal Feed ◽

Health Problems ◽

Plant Products ◽

Relationship Of ◽

The Relationship

Aflatoxins are produced by certain strains of fungi under warm, humid conditions during the growth of plants in the field and during storage of plant products (grains, legumes, nuts) and also they grow on some foodstuffs and animal feed. They are natural metabolism byproducts produced by molds and are considered one of the most dangerous compounds that cause carcinogenicity. If a person or animal consumes a food containing aflatoxin, they are vulnerable to many health problems. It has been found that the most dangerous aflatoxin is aflatoxin B1 because it works on cellular membranes as it inhibits RNA synthesis and is considered one of the factors that cause mutations due to its effect on DNA and also has an effect on the liver and is considered one of the strongest carcinogen compounds, which leads to the occurrence of tumors in the liver in case It is present in food at concentrations of 10 ppb. It was also found to have an immunosupressive effect on the body’s immune system.

Download Full-text

Measurement of Water Transport During Freezing in Mammalian Liver Tissue: Part II—The Use of Differential Scanning Calorimetry

Journal of Biomechanical Engineering ◽

10.1115/1.2834745 ◽

1998 ◽

Vol 120 (5) ◽

pp. 559-569 ◽

Cited By ~ 25

Author(s):

R. V. Devireddy ◽

J. C. Bischof

Keyword(s):

Water Transport ◽

Rat Liver ◽

Liver Tissue ◽

Freeze Substitution ◽

Sprague Dawley ◽

Transport Parameters ◽

Biophysical Parameters ◽

Scanning Calorimetry ◽

Tissue Slices ◽

Low Temperature Microscopy

There is currently a need for experimental techniques to assay the biophysical response (water transport or intracellular ice formation, IIF) during freezing in the cells of whole tissue slices. These data are important in understanding and optimizing biomedical applications of freezing, particularly in cryosurgery. This study presents a new technique using a Differential Scanning Calorimeter (DSC) to obtain dynamic and quantitative water transport data in whole tissue slices during freezing. Sprague-Dawley rat liver tissue was chosen as our model system. The DSC was used to monitor quantitatively the heat released by water transported from the unfrozen cell cytoplasm to the partially frozen vascular/extracellular space at 5°C/min. This technique was previously described for use in a single cell suspension system (Devireddy, et al. 1998). A model of water transport was fit to the DSC data using a nonlinear regression curve-fitting technique, which assumes that the rat liver tissue behaves as a two-compartment Krogh cylinder model. The biophysical parameters of water transport for rat liver tissue at 5°C/min were obtained as Lpg = 3.16 x 10−13 m3/Ns (1.9 μm/min-atm), ELp = 265 kJ/mole (63.4 kcal/mole), respectively. These results compare favorably to water transport parameters in whole liver tissue reported in the first part of this study obtained using a freeze substitution (FS) microscopy technique (Pazhayannur and Bischof, 1997). The DSC technique is shown to be a fast, quantitative, and reproducible technique to measure dynamic water transport in tissue systems. However, there are several limitations to the DSC technique: (a) a priori knowledge that the biophysical response is in fact water transport, (b) the technique cannot be used due to machine limitations at cooling rates greater than 40°C/min, and (c) the tissue geometric dimensions (the Krogh model dimensions) and the osmotically inactive cell volumes Vb, must be determined by low-temperature microscopy techniques.

Download Full-text

Metabolic Fate of 1,3-Butanediol in the Rat: Liver Tissue Slices Metabolism

Journal of Nutrition ◽

10.1093/jn/101.12.1711 ◽

1971 ◽

Vol 101 (12) ◽

pp. 1711-1718 ◽

Cited By ~ 19

Author(s):

M. A. Mehlman ◽

R. B. Tobin ◽

H. K. J. Hahn ◽

L. Kleager ◽

R. L. Tate

Keyword(s):

Rat Liver ◽

Liver Tissue ◽

Metabolic Fate ◽

Tissue Slices

Download Full-text

Peptide-fluorophore/AuNP conjugate-based two-photon excited fluorescent nanosensor for caspase-3 activity imaging assay in living cells and tissue

MedChemComm ◽

10.1039/c7md00177k ◽

2017 ◽

Vol 8 (7) ◽

pp. 1435-1439 ◽

Cited By ~ 3

Author(s):

Qingshan Ge ◽

Ningning Wang ◽

Jishan Li ◽

Ronghua Yang

Keyword(s):

Rat Liver ◽

Liver Tissue ◽

Caspase 3 ◽

Living Cells ◽

Live Cells ◽

Tissue Slices ◽

Two Photon

Via the assembly of two-photon dye (TPdye)-labeled peptides on the gold nanoparticle's surface, a novel two-photon excited (TPE) fluorescent nanosensor has been developed for the measurement of caspase-3 activity in live cells and rat liver tissue slices.

Download Full-text

Inhibition of RNA polymerase and RNA synthesis in rat liver nuclei by Bacillus thuringiensis exotoxin (thuringiensin)

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19752912 ◽

1975 ◽

Vol 40 (9) ◽

pp. 2912-2922 ◽

Cited By ~ 1

Author(s):

A. Čihák ◽

K. Horská ◽

K. Šebesta

Keyword(s):

Bacillus Thuringiensis ◽

Rna Polymerase ◽

Rat Liver ◽

Rna Synthesis ◽

Rat Liver Nuclei ◽

Liver Nuclei

Download Full-text

Postprandial Glycogen Content Is Increased in the Hepatocytes of Human and Rat Cirrhotic Liver

Cells ◽

10.3390/cells10050976 ◽

2021 ◽

Vol 10 (5) ◽

pp. 976

Author(s):

Natalia N. Bezborodkina ◽

Sergey V. Okovityi ◽

Boris N. Kudryavtsev

Keyword(s):

Rat Liver ◽

Liver Tissue ◽

Glycogen Content ◽

Glycogen Synthase ◽

Fibrous Tissue ◽

Glycogen Metabolism ◽

Liver Parenchyma ◽

Dry Mass ◽

Cirrhotic Liver ◽

Liver Biopsies

Chronic hepatitises of various etiologies are widespread liver diseases in humans. Their final stage, liver cirrhosis (LC), is considered to be one of the main causes of hepatocellular carcinoma (HCC). About 80–90% of all HCC cases develop in LC patients, which suggests that cirrhotic conditions play a crucial role in the process of hepatocarcinogenesis. Carbohydrate metabolism in LC undergoes profound disturbances characterized by altered glycogen metabolism. Unfortunately, data on the glycogen content in LC are few and contradictory. In this study, the material was obtained from liver biopsies of patients with LC of viral and alcohol etiology and from the liver tissue of rats with CCl4-induced LC. The activity of glycogen phosphorylase (GP), glycogen synthase (GS), and glucose-6-phosphatase (G6Pase) was investigated in human and rat liver tissue by biochemical methods. Total glycogen and its labile and stable fractions were measured in isolated individual hepatocytes, using the cytofluorometry technique of PAS reaction in situ. The development of LC in human and rat liver was accompanied by an increase in fibrous tissue (20- and 8.8-fold), an increase in the dry mass of hepatocytes (by 25.6% and 23.7%), and a decrease in the number of hepatocytes (by 50% and 28%), respectively. The rearrangement of the liver parenchyma was combined with changes in glycogen metabolism. The present study showed a significant increase in the glycogen content in the hepatocytes of the human and the rat cirrhotic liver, by 255% and 210%, respectively. An increased glycogen content in cells of the cirrhotic liver can be explained by a decrease in glycogenolysis due to a decreased activity of G6Pase and GP.

Download Full-text