Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-7-7
pubmed:abstractText
1. The effects of leucine and its metabolites, such as alpha-ketoisocaproate and ketone bodies, on the metabolic fluxes of tryptophan were investigated in isolated rat liver cells using [benzene ring-U-14C]- or [methylene-14C]-tryptophan. 2. Tryptophan metabolized through the kynureninase flux decreased while that metabolized to acetyl CoA remained unchanged in the presence of leucine or its metabolites. Accordingly an amount of tryptophan metabolized through the quinolinate-NAD pathway, which was estimated by subtracting an amount of tryptophan metabolized via the acetyl CoA flux from that via the kynureninase flux, was decreased in the presence of leucine or its metabolites. 3. Less quinolinate accumulated during incubation with metabolites of leucine, however, the amount was still sufficient to saturate quinolinate phosphoribosyltransferase (EC 2.4.2.19). 4. Leucine and its metabolites added in vitro at 1 mM level did not inhibit quinolinate phosphoribosyltransferase activity in rat liver homogenate. 5. The results indicate that a decrease in NAD biosynthesis from tryptophan caused by metabolites of leucine in the isolated rat liver cells was neither due to insufficient supply of quinolinate nor to direct inhibitory effect on quinolinate phosphoribosyltransferase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0300-9831
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-92
pubmed:dateRevised
2007-2-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Tryptophan metabolism by the isolated rat liver cells--effects of leucine and its metabolites.
pubmed:affiliation
School of Pharmacy, Kobe-Gakuin University, Japan.
pubmed:publicationType
Journal Article, In Vitro