scholarly journals STUDIES OF TWO TYPES OF ALKALINE PHOSPHATASE IN NUCLEI ISOLATED FROM THE LIVERS OF FED AND FASTED RATS BY A MODIFICATION OF THE BEHRENS TECHNIQUE

1955 ◽  
Vol 1 (4) ◽  
pp. 331-338 ◽  
Author(s):  
Arthur J. Emery ◽  
Alexander L. Dounce
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Liver ◽  
Liver Cell ◽  
Aqueous Media ◽  
Slight Modification ◽  
Magnesium Ions ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
The One ◽  
Fasted Rats

1. Rat liver nuclei were isolated from normal rats and rats fasted for 36 hours by a slight modification of the Behrens technique. 2. The nucleus of the rat liver cell contains two types of alkaline phosphatase. This confirms the previous findings on rat liver nuclei isolated in aqueous media. 3. The one type of alkaline phosphatase is not activated by magnesium ions, and this enzyme is very strongly bound to structural material of the nucleus. The other type of alkaline phosphatase is activated by magnesium ions, and this enzyme is probably free to diffuse from cytoplasm to nucleus and vice versa through the nuclear membrane. 4. Fasting caused a pronounced decrease of protein in general and of the alkaline phosphatase which is activated by magnesium ions from the nucleus of the rat liver cell, while the alkaline phosphatase that is not activated by magnesium was less affected.

Liver nuclear and microsomal CYP2E1-mediated metabolism of xenobiotics in rats chronically drinking an alcohol-containing liquid diet

2006 ◽  
Vol 22 (9) ◽  
pp. 367-374 ◽  
Author(s):  
María I. Díaz Gómez ◽  
Silvia L. Fanelli ◽  
Aurora M.A. Delgado de Layño ◽  
José A. Castro ◽  
Gerardo D. Castro
Keyword(s):  
Carbon Tetrachloride ◽  
Rat Liver ◽  
Alcohol Drinking ◽  
Liver Microsomes ◽  
Liquid Diet ◽  
Rat Liver Nuclei ◽  
Repetitive Exposure ◽  
Liver Nuclei ◽  
The One ◽  
Metabolism Of Xenobiotics

In previous studies from our laboratory, the presence in highly purified liver nuclei of metabolic pathways for processing ethanol (EtOH), N-nitrosodimethylamine (NDMA), carbon tetrachloride and chloroform was reported. All these chemicals are known to be metabolized in liver microsomes, via cytochrome P450 2E1 (CYP2E1)-mediated processes. In the present work we checked whether rat liver nuclei from rats chronically drinking an alcohol-containing liquid diet exhibited an enhanced ability to metabolize chemicals known to require CYP2E1 participation for given metabolic transformations. The nicotinamide adenosine dinucleotide phosphate (NADPH)-requiring metabolism of p-nitrophenol to p-nitrocathecol; the activation of carbon tetrachloride to trichloromethyl radicals, covalently binding to proteins; and the ring hydroxylation of aniline and o-toluidine were studied. Comparison of the obtained nuclear activities against the one present in the microsomal counterpart, and their respective response to the EtOH inductive effect after repetitive exposure to it, was studied. The obtained results showed that rat liver nuclei exhibited less pnitrophenol hydroxylase activity than microsomes, but it was inducible by repetitive alcohol drinking to equivalent levels of those of microsomes from control animals. Nuclei exhibited the ability to activate CCl4, which was significantly enhanced by alcohol drinking. Aniline was ring hydroxylated in liver microsomes but not in nuclei from either control or EtOH-treated animals. In contrast, nuclei and microsomes metabolized o-toluidine to ring hydroxylated products. They are considered less toxic in nature but other authors reported a genotoxic effect for one of them. The production of the ring hydroxylated metabolites was enhanced by repetitive EtOH drinking. Results suggest that nuclear metabolism of xenobiotics might be relevant for either activations or detoxications mediated by CYP2E1 and that repetitive exposure to EtOH might significantly modulate those processes. Toxicology and Industrial Health 2006; 22: 367-374.

scholarly journals Modulation by Exogenous Histones of Phosphorylation of Non-Histone Nuclear Proteins in Isolated Rat Liver Nuclei

1973 ◽  
Vol 248 (21) ◽  
pp. 7595-7600
Author(s):  
Edward M. Johnson ◽  
Giorgio Vidali ◽  
Virginia C. Littau ◽  
Vincent G. Allfrey
Keyword(s):  
Rat Liver ◽  
Nuclear Proteins ◽  
Isolated Rat Liver ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Isolated Rat
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