scholarly journals Effect of Glutathione and Cysteine on Rat Liver Tryptophan Oxygenase Activity

1971 ◽  
Vol 19 (3) ◽  
pp. 617-623
Author(s):  
ISAO ISHIGURO ◽  
RIKIO SHINOHARA
Keyword(s):  
Rat Liver ◽  
Tryptophan Oxygenase ◽  
Oxygenase Activity

scholarly journals The influence of some methodological factors on measurement of tryptophan oxygenase activities in crude homogenates of rat liver

1983 ◽  
Vol 209 (3) ◽  
pp. 831-836 ◽  
Author(s):  
L Stowell ◽  
J Mørland
Keyword(s):  
Rat Liver ◽  
Liver Tissue ◽  
Post Mortem ◽  
Temperature Dependent ◽  
Tryptophan Oxygenase ◽  
Oxygenase Activity ◽  
Liver Homogenates ◽  
Independent Reaction

1. With two different methods for assaying the tryptophan oxygenase activity in rat liver homogenates, the effects of some methodological factors on the activity of the enzyme were studied. 2. In fed, but not in starved, rats a compound(s) absorbing at 365 nm, interfering with the reading of kynurenine absorbance, disappeared gradually during incubation. 3. A correction for this tryptophan-independent reaction was necessary in order to determine correct tryptophan oxygenase activity. 4. Blood remaining in liver tissue post mortem can serve as a source of cofactor haem for tryptophan oxygenase, causing spuriously high values for the activity of the holoenzyme form of tryptophan oxygenase. 5. A rapid and progressive activation of tryptophan oxygenase post mortem occurs in undisrupted liver tissue, and this activation is temperature-dependent.

scholarly journals The effects of acetate, metal cations, phenobarbitone, porphyrogens and substrates of glycine acyltransferase on the utilization of haem by rat liver apo-(tryptophan pyrrolase)

1977 ◽  
Vol 164 (2) ◽  
pp. 431-438 ◽  
Author(s):  
A A B Badawy
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Metal Cations ◽  
Oxygenase Activity ◽  
Tryptophan Pyrrolase ◽  
Haem Oxygenase ◽  
Activity Enhancement

1. The utilization of haem by rat liver apo-(tryptophan pyrrolase) under basal conditions and after enhancement of the enzyme activity by various mechanisms was studied under the influence of treatments affecting various aspects of liver haem metabolism. 2. These treatments were: benzoate and p-aminobenzoate as substrates of glycine acyltransferase, acetate as an inhibitor of 5-aminolaevulinate synthase activity, enhancement of 5-aminolaevulinate dehydratase by aluminium, destruction of haem and inhibition of ferrochelatase by porphyrogens, increased haem utilization by phenobarbitone and enhancement of haem oxygenase activity by metal cations. 3. The results show that the haem saturation of the apoenzyme is sensitive to all these treatments. 4. The possible usefulness of tryptophan pyrrolase in studying the regulation of liver haem is suggested.

Effects of pyrazole on rat liver tryptophan oxygenase

Life Sciences ◽  
1976 ◽  
Vol 19 (4) ◽  
pp. 505-514 ◽  
Author(s):  
Hélène Rouach ◽  
Catherine Ribière ◽  
Joseph Nordmann ◽  
Roger Nordmann
Keyword(s):  
Rat Liver ◽  
Tryptophan Oxygenase
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