scholarly journals Identification of increased amounts of UDP-glucuronyltransferase protein in phenobarbital-treated chick-embryo liver cells

1983 ◽  
Vol 214 (2) ◽  
pp. 517-523 ◽  
Author(s):  
B Burchell ◽  
G J Pratt ◽  
I Duffy ◽  
L West
Keyword(s):  
Tissue Culture ◽  
Chick Embryo ◽  
Microsomal Fraction ◽  
Microsomal Protein ◽  
Liver Cells ◽  
Transferase Activity ◽  
Chick Embryos ◽  
Embryo Liver ◽  
Liver Microsomal Fraction ◽  
First Time

UDP-glucuronyltransferase activity of neonatal-chick liver or phenobarbital-treated chick-embryo liver catalysed the glucuronidation of 1-naphthol, 4-nitrophenol and 2-aminophenol. Only low transferase activity towards testosterone was detected, and activity towards bilirubin was not detectable. Liver microsomal transferase activity towards the three phenols was increased approx. 20-50-fold by phenobarbital treatment of chick embryos or by transfer of liver cells into tissue culture. A single form of UDP-glucuronyltransferase, which appears to catalyse the glucuronidation of these three phenols, was purified to near homogeneity from phenobarbital-treated chick-embryo liver microsomal fraction for the first time. The use of this purified enzyme as a standard protein facilitated the identification of this protein in chick-embryo liver microsomal fraction. Further, the accumulation of this microsomal protein was observed following phenobarbital treatment of chick embryos and during tissue culture of chick-embryo liver cells. The value of this model system for the study of the induction of UDP-glucuronyltransferase by drugs and hormones is discussed.

The influence of propranolol on the concentration of heme and on the activity of δ-aminolevulinate synthase in monolayers of chick embryo liver cells

1982 ◽  
Vol 31 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Orit Epstein ◽  
Nili Schoenfeld ◽  
Yehudit Greenblat ◽  
Meir Lahav ◽  
Abraham Atsmon
Keyword(s):  
Chick Embryo ◽  
Liver Cells ◽  
Aminolevulinate Synthase ◽  
Embryo Liver

Studies on the mechanism of in vitro estradiol-17-β induced synthesis of phosvitin in chick embryo liver cells

1976 ◽  
Vol 4 (6) ◽  
pp. 441-448 ◽  
Author(s):  
P. Carinci ◽  
A. Caruso ◽  
R. Evangelisti ◽  
E. Becchetti ◽  
G. Stabellini
Keyword(s):  
Chick Embryo ◽  
Liver Cells ◽  
Embryo Liver

scholarly journals Porphyrinogenic activity and ferrochelatase-inhibitory activity of sydnones in chick embryo liver cells

FEBS Letters ◽  
1986 ◽  
Vol 197 (1-2) ◽  
pp. 17-20 ◽  
Author(s):  
E.P. Sutherland ◽  
G.S. Marks ◽  
L.A. Grab ◽  
P.R.Ortiz de Montellano
Keyword(s):  
Chick Embryo ◽  
Inhibitory Activity ◽  
Liver Cells ◽  
Embryo Liver

scholarly journals Studies of endogenous inhibitors of microsomal glutathione S-transferase

1982 ◽  
Vol 207 (1) ◽  
pp. 57-64 ◽  
Author(s):  
T D Boyer ◽  
D Zakim ◽  
D A Vessey
Keyword(s):  
Microsomal Fraction ◽  
Hepatic Metabolism ◽  
Organic Layer ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Unilamellar Vesicles ◽  
Physiological Regulator ◽  
Liver Microsomal Fraction ◽  
Small Unilamellar Vesicles ◽  
Microsomal Glutathione

Glutathione S-transferase is present in rat liver microsomal fraction, but its activity is low relative to the transferase activity present in the soluble fraction of the hepatocyte. We have found, however, that the activity of microsomal glutathione S-transferase is increased 5-fold after treatment with small unilamellar vesicles made from phosphatidylcholine. The increase in activity is due to the removal of an inhibitor of the enzyme from the microsomal membrane. The inhibitor is present in the organic layer of a washed Folch extract of the microsomal fraction. When this fraction of the microsomal extract is reconstituted in the form of small unilamellar vesicles, it inhibits microsomal glutathione S-transferase that had been activated by prior treatment with small unilamellar vesicles of pure phosphatidylcholine, but does not affect the activity of unactivated microsomal glutathione S-transferase. The inhibitor did not seem to be formed during the isolation of the microsomal fraction, and hence may be a physiological regulator of microsomal glutathione S-transferase. In this regard, both free fatty acid (palmitate) and lysophosphatidylcholine were shown to inhibit the enzyme reversibly. The results indicate that the activity of microsomal glutathione S-transferase is far greater than appreciated until now, and that this form of the enzyme may be an important factor in the hepatic metabolism of toxic electrophiles.

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