Linked Life Data

6434392

Source:http://linkedlifedata.com/resource/pubmed/id/6434392

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1984-11-9
pubmed:abstractText
Bilirubin monoglucuronide is rapidly deconjugated when incubated with UDP and rat liver microsomal preparations at pH 5.1. The following evidence was found that this reaction is catalyzed by UDP-glucuronyltransferase: (i) unconjugated bilirubin and UDP-glucuronic acid were identified as the reaction products; (ii) Gunn rat microsomal preparations lack bilirubin UDP-glucuronyltransferase deficiency and do not catalyze the deconjugation reaction, and (iii) neither saccharo-1,4-lactone, a beta-glucuronidase inhibitor, nor butylated hydroxytoluene, an inhibitor of spontaneous isomerisation, affect the rate of the deconjugation reaction. Deconjugation appears to be the reverse of UDP-glucuronyltransferase-catalyzed glucuronidation. The conditions for the reverse reaction differ in the following aspects from those of the forward reaction: (i) nucleotide triphosphates stimulate the reverse reaction probably allosterically; (ii) UDP-N-acetylglucosamine stimulates the forward reaction but has no effect on the reverse reaction; (iii) the optimal pH for the reverse reaction is pH 5.1 and for the forward reaction is pH 7.8, and (iv) Mg++ ion is not required for the reverse reaction but stimulates the forward reaction. Detergents stimulate both reactions. Stimulation of the reverse reaction by nucleotide triphosphates and detergents is mutually independent and additive which suggests different mechanisms of action. Deconjugation reactions may become important during parenchymatous liver disease when, as a result of anaerobic glycolysis, intracellular pH decreases. Elevated levels of unconjugated bilirubin in the serum of patients with parenchymatous liver disease may be a sign of sick liver cells rather than decreased UDP-glucuronyltransferase activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0270-9139
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
918-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
UDP-glucuronyltransferase-catalyzed deconjugation of bilirubin monoglucuronide.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't