scholarly journals Effects of Whole-body X-irradiation on the Incorporation of 3H-orotic acid into Nuclear RNA Fractions of Rat Liver

1969 ◽  
Vol 10 (1) ◽  
pp. 17-24
Author(s):  
Saburo OMATA ◽  
Shogo ICHII ◽  
Nagasumi YAGO ◽  
Shigeru KOBAYASHI
Keyword(s):  
Rat Liver ◽  
Orotic Acid ◽  
Whole Body ◽  
Nuclear Rna ◽  
X Irradiation

Stimulation of cholesterol biosynthesis from acetate in rat liver and adrenals by whole body X-irradiation

1959 ◽  
Vol 196 (6) ◽  
pp. 1231-1237 ◽  
Author(s):  
R. Gordon Gould ◽  
Virginia L. Bell ◽  
Edith H. Lilly
Keyword(s):  
Rat Liver ◽  
Adrenal Glands ◽  
Cholesterol Biosynthesis ◽  
Whole Body ◽  
Hepatic Cholesterol ◽  
Reliable Measure ◽  
Proximate Cause ◽  
Synthetic Rate ◽  
X Irradiation ◽  
Stimulation Of

Whole body x-irradiation resulted in an increased cholesterol biosynthesis in rat liver and adrenal glands, as measured by the rate of incorporation of either acetate-1-C14 or H3OH in intact animals. The effect was significant 24 hours postirradiation but was much larger at 48 hours, and was proportional to dosage over the range 300–2400 r. In liver the increase in rate was about 100%/100 r. Intestine showed no effect and carcass only a slight increase. Mice showed a small increase in hepatic cholesterol biosynthesis but rabbits and guinea pigs no significant change. Rats injected with both acetate-1-C14 and H3OH gave reasonably constant ratios of C14 and H3 in liver and carcass cholesterol in control and irradiated animals, supporting the hypothesis that the use of acetate-1-C14 in whole animals under standard conditions is a reliable measure of cholesterol biosynthetic rate. The proximate cause of the increased rate of cholesterol synthesis is postulated to be the decreased concentration; in liver a decrease of 0.12 mg/gm was correlated with a doubling of the synthetic rate.

scholarly journals Effect of Whole-body X-irradiation on the Microsomal Drug-metabolizing Enzyme System in Rat Liver

1969 ◽  
Vol 10 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Shogo ICHII ◽  
Nagasumi YAGO ◽  
Shigeru KOBAYASHI ◽  
Saburo OMATA
Keyword(s):  
Rat Liver ◽  
Enzyme System ◽  
Whole Body ◽  
Drug Metabolizing Enzyme ◽  
X Irradiation ◽  
Metabolizing Enzyme

Metabolism of high molecular weight, polydisperse, rapidly labeled nuclear RNA in rat liver

1968 ◽  
Vol 46 (12) ◽  
pp. 1497-1505 ◽  
Author(s):  
Maurice Brossard ◽  
Louis Nicole
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Rat Liver ◽  
Ribosomal Rna ◽  
Base Composition ◽  
Orotic Acid ◽  
Chromosomal Origin ◽  
Base Analysis ◽  
Nuclear Rna ◽  
Kinetics Of

Studies of the metabolism of rat liver RNA showed the existence of two species of rapidly labeled nuclear RNA: a 45 S preribosomal type of nucleolar origin, and a 6–50 S polydisperse RNA of chromosomal origin. The kinetics of labeling with orotic acid-14C and the nature of the latter RNA have been investigated. The following findings are reported, (1) This RNA is composed of at least four main classes of RNA having sedimentation coefficients of approximately 45, 35, 24, and 18 S. (2) Except for the 18 S class which seems to be an end product, the three other classes have a rapid turnover and do not appear to leave the nucleus. (3) Base analysis after 32P incorporation indicates that these four classes of RNA have a similar base composition with a G+C/A + U ratio in the range of 0.98–1.07, which resembles DNA more closely than ribosomal RNA. (4) The 6–50 S polydisperse RNA has a different metabolism than that of the 45 S preribosomal type and there is no precursor-to-product relationship between these two species of RNA.

scholarly journals Pituitary Effect on Synthesis of Deoxyribonucleic Acid in Regenerating Rat Liver following Whole-body X-irradiation

Nature ◽  
1961 ◽  
Vol 192 (4809) ◽  
pp. 1309-1309 ◽  
Author(s):  
D. M. GOULD ◽  
K. W. FLOYD ◽  
R. W. WHITEHEAD ◽  
J. L. SANDERS
Keyword(s):  
Rat Liver ◽  
Deoxyribonucleic Acid ◽  
Whole Body ◽  
Regenerating Rat Liver ◽  
X Irradiation

scholarly journals Whole-body X-irradiation Induces Acute and Transient Expression of Heme Oxygenase-1 in Rat Liver

2002 ◽  
Vol 43 (2) ◽  
pp. 205-205 ◽  
Author(s):  
KEIKO SUZUKI ◽  
MASAHIKO MORI ◽  
FUMIHIKO KUGAWA ◽  
HIROSHI ISHIHARA
Keyword(s):  
Transient Expression ◽  
Heme Oxygenase ◽  
Rat Liver ◽  
Whole Body ◽  
Heme Oxygenase 1 ◽  
X Irradiation

scholarly journals The effect of whole-body X-irradiation of guinea pigs on liver ribonucleic acid synthesis

1970 ◽  
Vol 116 (3) ◽  
pp. 503-514 ◽  
Author(s):  
E. J. Hidvégi ◽  
Elisabeth Bölöni ◽  
J. Holland ◽  
F. Antoni ◽  
V. Várterész
Keyword(s):  
Orotic Acid ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Polymerase Activity ◽  
Whole Body ◽  
Sucrose Density Gradient Centrifugation ◽  
Polyuridylic Acid ◽  
X Irradiation ◽  
Rna Polymerase Activity

1. Liver RNA synthesis was studied within 24h after whole-body X-irradiation of guinea pigs that had been starved for 22–24h. 2. Microsomal RNA was labelled in vivo for 3h with [14C]orotic acid and the isolated labelled RNA was fractionated by sucrose-density-gradient centrifugation. Incorporation was 50–100% higher between 3 and 12h after 2000rd X-irradiation and at 22h was not elevated any further. Whole nuclear RNA was labelled with [14C]orotic acid for 15min. At 5h after irradiation the incorporation showed a 50–100% increase. Incorporation increased in all types of RNA studied. 3. The RNA phosphorus/DNA phosphorus ratio of whole liver gradually increased after X-irradiation. Maximal increase was found between 24 and 36h, which corresponds to a value about 40% above that of the starved control. The RNA phosphorus content of isolated ribonucleoproteins obtained from various cell fractions of the liver was similarly increased after X-irradiation. 4. Liver microsomes were obtained from X-irradiated and control animals. Microsomes were incubated in vitro with [14C]phenylalanine in the presence and absence of polyuridylic acid. After the incubation the microsomes were fractionated by sucrose-density-gradient centrifugation. The polyuridylic acid enhancement was twice as great in the microsomes of the control preparation as in the irradiated one. The experiment demonstrated a higher saturation of microsomes by endogenous messenger after X-irradiation. 5. RNA polymerase activity of the purified nuclear preparation was assayed. The activity of the Mg2+-dependent RNA polymerase activity was 50 and 200% respectively above the control values at 6 and 9h after X-irradiation. 6. Animals were treated with actinomycin D shortly before X-irradiation. This treatment abolished the radiation-induced enrichment of polyribosomes and the increase of protein-synthesizing activity. The effect of X-irradiation on the transcription of the genetic code of the liver is discussed.

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