scholarly journals A NUCLEAR MEMBRANE CHANGE AFTER PARTIAL HEPATECTOMY

1964 ◽  
Vol 23 (3) ◽  
pp. 511-518 ◽  
Author(s):  
Susumu Kishimoto ◽  
Irving Lieberman
Keyword(s):  
Electrophoretic Mobility ◽  
Partial Hepatectomy ◽  
Nuclear Membrane ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Rate Increase ◽  
Fold Increase ◽  
Liver Nuclei ◽  
The Difference ◽  
Membrane Change

Partial hepatectomy (67 per cent extirpation) of the rat leads to a change in the membrane of liver nuclei (purified with citric acid) detectable as an increase in electrophoretic mobility. No change is detectable 2 hours after the operation, but between 2 and 6 hours about a 1.4-fold increase in mobility occurs after which the mobility becomes constant at the elevated level. Removal of only 10 per cent of the liver causes no detectable change in 6 hours. Bilateral adrenalectomy immediately before partial hepatectomy does not affect the development of the nuclear change. Actinomycin D and p-fluorophenylalanine, but not noradrenalin, ionizing radiation, or EDTA, suppress the increase in electrophoretic mobility. The level of actinomycin D required to block the nuclear membrane change is 6 times greater than that necessary to prevent the rate increase in hepatic RNA metabolism that follows removal of part of the liver. This discrepancy and the difference in the response to noradrenalin indicate that, at least initially, the nuclear membrane change and the change in the rate of RNA synthesis are independent processes. The inability of EDTA to block the nuclear membrane change shows that the Zn++ requirement for DNA replication is not related to the events that lead to the alteration in the electrokinetic properties of liver nuclei.

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.

Hepatic blood supply and control of deoxyribonucleic acid synthesis in liver

1965 ◽  
Vol 208 (5) ◽  
pp. 896-902 ◽  
Author(s):  
Irving Lieberman ◽  
John Short
Keyword(s):  
Portal Vein ◽  
Partial Hepatectomy ◽  
Nuclear Membrane ◽  
Rna Synthesis ◽  
Acid Synthesis ◽  
Portal Vein Branch ◽  
Deoxyribonucleic Acid Synthesis ◽  
Branch Vessel ◽  
Hepatic Portal ◽  
And Control

Permanent ligation of the branch of the hepatic portal vein supplying a portion (67%) of the liver causes, in the nonligated lobes, increases in the rate of RNA synthesis, in the electrophoretic mobility of the nuclei, and in DNA formation that are indistinguishable from those that follow partial hepatectomy. Temporary ligation of the branch vessel causes some or all of these changes in the nonligated lobes depending on the length of the ligation time. Thus, a ligation period of 0.5–2 min produces the alterations in RNA formation and in the nuclear membrane, but hepatic DNA synthesis is unaffected. Ligation of the branch vessel for 10 min yields, in addition, a marked increase in DNA formation. The possibility is considered that the changes in RNA synthesis and in the nuclear membrane result directly from the vascular disturbance caused by partial hepatectomy or the ligation of the portal vein branch. At least some of the alterations required to stimulate DNA formation, however, appear to have a different etiology, possibly related to a loss of liver function.

scholarly journals THE DISORGANIZATION OF HEPATIC CELL NUCLEOLI INDUCED BY ETHIONINE AND ITS REVERSAL BY ADENINE

1968 ◽  
Vol 36 (2) ◽  
pp. 313-328 ◽  
Author(s):  
Hisashi Shinozuka ◽  
Peter J. Goldblatt ◽  
Emmanuel Farber
Keyword(s):  
Electron Microscope ◽  
Nuclear Membrane ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Hepatic Cell ◽  
Short Term ◽  
Hepatic Cells ◽  
Basic Reaction ◽  
Reaction Patterns

The structure of nuclei and nucleoli of hepatic cells after short-term ethionine administration was investigated with the electron microscope. By 1½ hr after the injection, a distinct alteration occurred in the nucleoli which was characterized by the appearance of electron-opaque masses in the nucleolonema. After 6–8 hr, the nucleoli showed partial fragmentation into small, dense masses. Large aggregates of interchromatinic granules appeared in the nucleoplasm. Condensation of chromatin became prominent in the nucleoplasm particularly along the nuclear membrane. By 12 hr almost complete fragmentation of nucleoli had occurred. The administration of adenine or methionine at 4 hr prevented the development of nucleolar changes. Also, adenine administration at 8 hr after ethionine completely reversed the nucleolar lesion by 12 hr. After methionine administration at 8 hr, many nucleoli showed incomplete reconstruction with many twisted ropelike structures when viewed 4 hr later. Identical structures were found when adenine was given at 8 hr, and animals were sacrificed 2 hr later. On the basis of this observation, the simplified structures of nucleoli found 2 hr after adenine or 4 hr after methionine appeared to be precursors of the nucleolonema. It is suggested that nucleoli show at least two basic reaction patterns to inhibitors of RNA synthesis, one typified by actinomycin D and one by ethionine.

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.

Inorganic phosphate and Na+ increases in liver after partial hepatectomy

1965 ◽  
Vol 208 (5) ◽  
pp. 903-907 ◽  
Author(s):  
Irving Lieberman ◽  
James L. Gingold ◽  
Patricia Kane ◽  
John Short
Keyword(s):  
Protein Synthesis ◽  
Electrophoretic Mobility ◽  
Partial Hepatectomy ◽  
Inorganic Phosphate ◽  
Rna Synthesis ◽  
Portal Branch ◽  
Early Increase ◽  
Branch Vessel

After removal of two-thirds of the liver, no changes occur in the hepatic content of K+, Ca++, Mn++, but liver P1 and Na+ rise. The increase in P1 (20–30%) is more than half maximal 5 min after the operation, and with Na+ (about 30%) the rise is complete at this time. These increases appear to represent intracellular rather than extracellular changes. They are related to the amount of liver removed and, judging by the inability of puromycin to affect the ion rises, they are not dependent on prior protein synthesis. Permanent ligation and ligation for 10 min of the portal branch to the 67% portion of the liver causes an early increase in the P1 content of the 33% part of the liver, but the Na+ rise occurs only after a delay of about 4.5 hr. Neither the P1 nor the Na+ rise appears to be causally related to the changes in hepatic RNA synthesis and nuclear electrophoretic mobility that result from partial hepatectomy or ligation of the portal branch vessel.

scholarly journals Ribonucleic acid synthesis in vitro in primary spermatocytes isolated from rat testis

1977 ◽  
Vol 168 (1) ◽  
pp. 23-31 ◽  
Author(s):  
J. Anton Grootegoed ◽  
Anne H. Grollé-Hey ◽  
Focko F. G. Rommerts ◽  
Henk J. Van Der Molen
Keyword(s):  
Electrophoretic Mobility ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Marked Change ◽  
Acid Synthesis ◽  
Specific Pattern ◽  
28S Rrna ◽  
Phenol Extraction

The incorporation of [3H]uridine into RNA was studied quantitatively (by incorporation of [3H]uridine into acid-precipitable material) and qualitatively (by phenol extraction and electrophoretic separation of RNA in polyacrylamide gels) in preparations enriched in primary spermatocytes, obtained from testes of rats 26 or 32 days old. The rate of incorporation of [3H]uridine into RNA of isolated spermatocytes was constant during the first 8h of incubation, after which it decreased, but the decreased rate of incorporation was not reflected in a marked change in electrophoretic profiles of labelled RNA. In isolated spermatocytes, [3H]uridine was incorporated mainly into heterogeneous RNA with a low electrophoretic mobility. Most of this RNA was labile, as shown when further RNA synthesis was inhibited with actinomycin D. Spermatocytes in vivo also synthesized heterogeneous RNA with a low electrophoretic mobility. A low rate of incorporation of [3H]uridine into rRNA of isolated spermatocytes was observed. The cleavage of 32S precursor rRNA to 28S rRNA was probably retarded in spermatocytes in vitro as well as in vivo. RNA synthesis by preparations enriched in early spermatids or Sertoli cells was qualitatatively different from RNA synthesis by the spermatocyte preparations. It is concluded that isolated primary spermatocytes maintain a specific pattern of RNA synthesis, which resembles RNA synthesis in spermatocytes in vivo. Therefore isolated spermatocytes of the rat can be used for studying the possible regulation of RNA synthesis during the meiotic prophase.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

scholarly journals Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin

1973 ◽  
Vol 134 (4) ◽  
pp. 1103-1113 ◽  
Author(s):  
A. Betteridge ◽  
M. Wallis
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Rna Synthesis ◽  
Glucose Utilization ◽  
Actinomycin D ◽  
Hormone Synthesis ◽  
Pituitary Glands ◽  
Hormone Biosynthesis ◽  
Stimulation Of

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.

Improving Fatigue Life of Riveted Joints by Rivet Hole Sizing

2014 ◽  
Vol 598 ◽  
pp. 141-146
Author(s):  
Adam Lipski ◽  
Zbigniew Lis
Keyword(s):  
Fatigue Life ◽  
Fold Increase ◽  
Fatigue Tests ◽  
Aviation Industry ◽  
Lap Joint ◽  
Riveted Joints ◽  
Riveting Process ◽  
The Difference ◽  
Structural Connection ◽  
The Impact

The aim of this paper is to assess the impact of the rivet hole sizing process on the fatigue life based on the example of the structural connections characteristic for riveted joints used in aviation industry. Test specimens reflected the structural connection consisting in a riveted lap joint of an airplane plating stiffened with a T-bar. Connected plates and the T-bar are made of D16CzATW aluminum alloy. 3 mm diameter oval head solid rivets for aviation-related purposes were made of PA24 aluminum. During fatigue tests, individual specimens with non-sized holes and with sized holes were subjected to uniaxial, one-sided, fixed-amplitude loading (R = 0). It can be concluded from the fatigue life comparison that introduction of an additional operation in the riveting process, i.e. the hole sizing, results in significant, about two-fold increase of the fatigue life of the riveted structural connection, even at slight sizing degree. The difference of the specimen damage nature was observed between specimens with sized and non-sized holes.

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