scholarly journals Metabolic Hydrolysis of Isoniazid by Subcellular Fractions of Rat Liver

1984 ◽  
Vol 6 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Toshiaki SENDO ◽  
Atsuko NODA ◽  
Hiroshi NODA ◽  
Kuang-Yang HSU ◽  
Yuzo YAMAMOTO
Keyword(s):  
Rat Liver ◽  
Subcellular Fractions ◽  
Hydrolysis Of

scholarly journals Hydrolysis of Retinol Palmitate by Rat Liver

1966 ◽  
Vol 241 (1) ◽  
pp. 57-64 ◽  
Author(s):  
S. Mahadevan ◽  
N.I. Ayyoub ◽  
O.A. Roels
Keyword(s):  
Rat Liver ◽  
Hydrolysis Of

The Prediction of the Hepatic Clearance of Tanshinone IIA in Rat Liver Subcellular Fractions: Accuracy Improvement

2008 ◽  
Vol 9 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Guang-Ji Wang ◽  
Peng Li ◽  
Jing Li ◽  
Qian Zhang ◽  
Xin Liu ◽  
...  
Keyword(s):  
Rat Liver ◽  
Hepatic Clearance ◽  
Subcellular Fractions ◽  
Tanshinone Iia ◽  
Accuracy Improvement

Activation of styrene to styrene oxide in hepatocytes and subcellular fractions of rat liver

1984 ◽  
Vol 23 (2) ◽  
pp. 157-162 ◽  
Author(s):  
G. Belvedere ◽  
E. Elovaara ◽  
H. Vainio
Keyword(s):  
Rat Liver ◽  
Styrene Oxide ◽  
Subcellular Fractions

scholarly journals Chain extension of ribonucleic acid by enzymes from rat liver cytoplasm

1968 ◽  
Vol 109 (4) ◽  
pp. 485-494 ◽  
Author(s):  
N. M. Wilkie ◽  
R. M. S. Smellie
Keyword(s):  
Rat Liver ◽  
Alkaline Hydrolysis ◽  
Actinomycin D ◽  
Chain Extension ◽  
Supernatant Fraction ◽  
Inorganic Pyrophosphate ◽  
Optimum Ph ◽  
Microsome Fraction ◽  
Hydrolysis Of ◽  
Generating System

1. The 105000g supernatant fraction of rat liver catalyses the incorporation of ribonucleotides from ribonucleoside triphosphates into polyribonucleotide material. The reaction requires Mg2+ ions and is enhanced by the addition of an ATP-generating system and RNA, ATP, UTP and CTP but not GTP are utilized in this reaction. In the case of UTP, the product is predominantly a homopolymer containing 2–3 uridine residues, and there is evidence that these may be added to the 3′-hydroxyl ends of RNA or oligoribonucleotide primers. 2. The microsome fraction of rat liver incorporates ribonucleotides from ATP, GTP, CTP and UTP into polyribonucleotide material. This reaction requires Mg2+ ions and is enhanced slightly by the addition of an ATP-generating system, and by RNA but not DNA. Supplementation of the reaction mixture with the three complementary ribonucleoside 5′-triphosphates greatly increases the utilization of a single labelled ribonucleoside 5′-triphosphate. The optimum pH is in the range 7·0–8·5, and the reaction is strongly inhibited by inorganic pyrophosphate and to a much smaller degree by inorganic orthophosphate. It is not inhibited by actinomycin D or by deoxyribonuclease. In experiments with [32P]UTP in the absence of ATP, GTP and CTP, 80–90% of 32P was recovered in UMP-2′ or −3′ after alkaline hydrolysis of the reaction product. When the reaction mixture was supplemented with ATP, GTP and CTP, however, about 40% of the 32P was recovered in nucleotides other than UMP-2′ or −3′. Although the reactions seem to lead predominantly to the synthesis of homopolymers, the possibility of some formation of some heteropolymer is not completely excluded.

scholarly journals The roles of phospholipase D and a GTP-binding protein in guanosine 5′-[γ-thio]triphosphate-stimulated hydrolysis of phosphatidylcholine in rat liver plasma membranes

1990 ◽  
Vol 272 (3) ◽  
pp. 749-753 ◽  
Author(s):  
K M Hurst ◽  
B P Hughes ◽  
G J Barritt
Keyword(s):  
Rat Liver ◽  
Phospholipase D ◽  
Plasma Membranes ◽  
Regulatory Protein ◽  
Gtp Binding ◽  
Liver Plasma Membranes ◽  
Low Concentrations ◽  
Rat Liver Plasma Membranes ◽  
Triton X ◽  
Hydrolysis Of

1. Guanosine 5′-[gamma-thio]triphosphate (GTP[S]) stimulated by 50% the rate of release of [3H]choline and [3H]phosphorylcholine in rat liver plasma membranes labelled with [3H]choline. About 70% of the radioactivity released in the presence of GTP[S] was [3H]choline and 30% was [3H]phosphorylcholine. 2. The hydrolysis of phosphorylcholine to choline and the conversion of choline to phosphorylcholine did not contribute to the formation of [3H]choline and [3H]phosphorylcholine respectively. 3. The release of [3H]choline from membranes was inhibited by low concentrations of SDS or Triton X-100. Considerably higher concentrations of the detergents were required to inhibit the release of [3H]phosphorylcholine. 4. Guanosine 5′-[beta gamma-imido]triphosphate and guanosine 5′-[alpha beta-methylene]triphosphate, but not adenosine 5′-[gamma-thio]-triphosphate, stimulated [3H]choline release to the same extent as did GTP[S]. The GTP[S]-stimulated [3H]choline release was inhibited by guanosine 5′-[beta-thio]diphosphate, GDP and GTP but not by GMP. 5. It is concluded that, in rat liver plasma membranes, (a) GTP[S]-stimulated hydrolysis of phosphatidylcholine is catalysed predominantly by phospholipase D with some contribution from phospholipase C, and (b) the stimulation of phosphatidylcholine hydrolysis by GTP[s] occurs via a GTP-binding regulatory protein.

scholarly journals DISTRIBUTION OF METALS IN SUBCELLULAR FRACTIONS OF RAT LIVER

1957 ◽  
Vol 226 (2) ◽  
pp. 911-920 ◽  
Author(s):  
Ralph E. Thiers ◽  
Bert L. Vallee
Keyword(s):  
Rat Liver ◽  
Subcellular Fractions

LOCALIZATION AND CHARACTERIZATION OF CHOLINESTERASE IN SUBCELLULAR FRACTIONS OF RAT BRAIN AND BEEF PITUITARY

1961 ◽  
Vol 39 (9) ◽  
pp. 1335-1345 ◽  
Author(s):  
Surendra S. Parmar ◽  
Morley C. Sutter ◽  
Mark Nickerson
Keyword(s):  
Rat Brain ◽  
Cholinesterase Activity ◽  
Succinic Dehydrogenase ◽  
Anterior Lobe ◽  
Subcellular Fractions ◽  
Posterior Pituitary ◽  
Low Concentrations ◽  
Pituitary Glands ◽  
Hydrolysis Of

Fresh rat brains and fresh anterior and posterior pituitary glands of beef were separated by differential centrifugation into subcellular fractions, characterized on the basis of sedimentation and succinic dehydrogenase activity. Cholinesterase activity was measured by both manometric and colorimetric methods, the results of which were comparable. Cholinesterase activity of rat brain was found mainly in the microsome and supernatant fractions. It was quite uniformly distributed in all subcellular fractions of both anterior and posterior pituitary. Comparisons of the relative rates of hydrolysis of acetylthiocholine and butyrylthiocholine, and of inhibition by eserine, indicated that brain contains a much higher percentage of acetylcholinesterase than do both lobes of the pituitary, which contain relatively low concentrations of the specific enzyme. Total cholinesterase activity and its sensitivity to inhibition by eserine in the posterior pituitary were found to be midway between those of the anterior lobe and of the brain, from which the posterior pituitary was derived during embryological development.

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