Linked Life Data

9696700

Source:http://linkedlifedata.com/resource/pubmed/id/9696700

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 1
pubmed:dateCreated
1998-8-6
pubmed:abstractText
Previous studies indicated that uridine is essentially cleared in a single pass through a rat liver and replaced in a highly regulated manner by uridine formed presumably by de novo synthesis. We report a cellular basis for the catabolic component of this apparent paradox by dissociation of the liver with collagenase into two cell fractions, hepatocytes and a nonparenchymal cell population. Suspensions of the nonparenchymal cells rapidly cleave uridine to uracil, whereas in hepatocytes this activity was <5% of that in nonparenchymal cells. Conversely, hepatocytes cause extensive degradation of uracil to -alanine. These differences correlate with the uridine phosphorylase and dihydrouracil dehydrogenase activity in cell-free extracts of each cell type. We have documented the existence of a Na+-dependent, nitrobenzylthioinosine-insensitive transport system for uridine in the parenchymal cells (Michaelis constant 46 +/- 5 microM) that achieves a three- to fourfold concentration gradient in hepatocytes. A similar system is present in the nonparenchymal cell population. In addition, a highly specific and active Na+-dependent transport system for beta-alanine, the primary catabolic metabolite of uracil, has been demonstrated in hepatocytes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G1018-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Discrete roles of hepatocytes and nonparenchymal cells in uridine catabolism as a component of its homeostasis.
pubmed:affiliation
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.