scholarly journals Phosphotriesters in rat liver deoxyribonucleic acid after the administration of the carcinogen NN-dimethylnitrosamine in vivo

1975 ◽  
Vol 145 (3) ◽  
pp. 475-482 ◽  
Author(s):  
P J O'Connor ◽  
G P Marigison ◽  
A W Craig
Keyword(s):  
Rat Liver ◽  
Deoxyribonucleic Acid ◽  
Methylation Pattern ◽  
Rat Livers

After treatment with NN-di[14C]methylnitrosamine, samples of DNA were isolated from rat livers by a conventional phenol procedure and examined for the presence of phosphotriesters. A method of capable of detecting relatively small amounts of 14C-labelled phosphotriesters was developed and used to establish that these products account for 10-12% of the total methylation pattern found after treatment with this agent in vitro. The significance of the presence of phosphotriesters in DNA is discussed.

scholarly journals Transcription of fractionated mammalian chromatin by mammalian ribonucleic acid polymerase. Demonstration of temperature-dependent rifampicin-resistant initiation sites in euchromatin deoxyribonucleic acid

1974 ◽  
Vol 143 (1) ◽  
pp. 73-81 ◽  
Author(s):  
C. James Chesterton ◽  
Barbara E. H. Coupar ◽  
Peter H. W. Butterworth
Keyword(s):  
Rna Polymerase ◽  
Rat Liver ◽  
Deoxyribonucleic Acid ◽  
Temperature Dependent ◽  
Fractionation Method ◽  
Liver Nuclei ◽  
Nascent Rna ◽  
Chromatin Fractionation

The chromatin fractionation method of Frenster et al. (1963) as modified by Leake et al. (1972) was used to prepare fragments of euchromatin from rat liver nuclei. These remain soluble in 5mm-MgCl2, and contain DNA of maximum mol.wt. 1×106–2×106. The fragments were separated from condensable chromatin on a sucrose gradient. Euchromatin contains endogenous DNA-dependent RNA polymerase, and most of the nascent RNA labelled in vivo or in vitro. Euchromatin fragments allow initiation of transcription by added purified rat liver form-B RNA polymerase and contain temperature-dependent rifampicin-resistant initiation sites for the form-B enzyme. These findings indicate that transcription of the euchromatin regions of interphase chromosomes is not initiated in condensed chromatin, but is initiated within the euchromatin stretches. Condensable chromatin also contains most of these activities, but is not associated with nascent RNA.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation

Udp glucuronyltransferase and phenolsulfotransferase from rat liver in vivo and in vitro—III

1975 ◽  
Vol 24 (4) ◽  
pp. 517-521 ◽  
Author(s):  
Gerard J. Mulder ◽  
Arnold H.E. Pilon
Keyword(s):  
Rat Liver

scholarly journals The effects of salicylate on the activity of rat liver tyrosine–2-oxoglutarate aminotransferase in vitro and in vivo

1972 ◽  
Vol 126 (2) ◽  
pp. 347-350 ◽  
Author(s):  
A. A.-B. Badawy
Keyword(s):  
Rat Liver ◽  
Pyridoxal Phosphate ◽  
Actinomycin D ◽  
Sodium Salicylate ◽  
Intraperitoneal Administration ◽  
Tyrosine Aminotransferase ◽  
Major Effect ◽  
Endogenous Activity

1. Salicylate, in concentrations of 0.25mm and above, enhances the basal activity of tyrosine–2-oxoglutarate aminotransferase in homogenates of rat liver incubated in the absence of added pyridoxal 5′-phosphate (endogenous activity). The effect is decreased by increasing the concentration of the cofactor. 2. The intraperitoneal administration of sodium salicylate enhances the activity of rat liver tyrosine aminotransferase; the major effect during the first hour being on the enzyme in the absence of added pyridoxal phosphate. Actinomycin D prevents the induction of the enzyme by cortisol and tryptophan. Induction by pyridoxine or salicylate is 50% inhibited by actinomycin D. The effects of the injections of various combinations of cortisol, pyridoxine and salicylate were also studied in the absence or presence of actinomycin D. 3. It is suggested that salicylate induces rat liver tyrosine aminotransferase by displacing its protein-bound cofactor and that a cofactor-type induction of the hepatic enzyme occurs in pyridoxine-treated rats.

Studies on the induction of rat hepatic CYP1A, CYP2B, CYP3A and CYP4A subfamily form mRNAs in vivo and in vitro using precision-cut rat liver slices

Xenobiotica ◽  
2003 ◽  
Vol 33 (5) ◽  
pp. 511-527 ◽  
Author(s):  
C. Meredith ◽  
M. P. Scott ◽  
A. B. Renwick ◽  
R. J. Price ◽  
B. G. Lake
Keyword(s):  
Rat Liver ◽  
Liver Slices
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