Linked Life Data

2918843

Source:http://linkedlifedata.com/resource/pubmed/id/2918843

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1989-4-4
pubmed:abstractText
The roles of subcellular components and, in particular, cytosol fractions and beta-nicotinamide adenine dinucleotide phosphate, reduced form (NADPH), in the regulation of rat hepatic and renal 5'-deiodination during fasting were assessed. 5'-deiodinase (5'-DI) activities in reaction mixtures were measured by using outer ring 125I-radiolabelled reverse triiodothyronine (rT3) as a substrate in the presence of 200 mumol/L NADPH. Subcellular components from rats fed ad libitum or fasted for 24, 48 or 72 hours were prepared by standard differential centrifugation. Cytosol was chromatographed on a Sephadex G-50 column to obtain Fraction A of molecular weight (Mr) greater than 60,000 and Fraction B of Mr approximately 13,000 and to exclude reduced glutathione (GSH) (Mr less than 400). 5'-DI activity in liver homogenates was reduced by 42% at 24 hours and by 59% at 48 hours of fasting. In reconstitution experiments, liver microsomes showed a progressive loss of 5'-DI activity, reaching a maximal reduction of 46% at 72 hours of fasting. Activation of microsomal deiodinase by whole liver cytosol was also significantly reduced at 24 hours of fasting and achieved a maximal reduction of 5'-DI activation of 42% at 48 hours before substantial but incomplete recovery at 72 hours. Cytosolic Fraction A and B were assessed in combination with fed microsomes and NADPH. A close correlation was demonstrated between the loss of hepatic 5'-DI supportive activity in whole cytosol and that of Fraction B but not A during fasting.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0026-0495
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
230-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Rat hepatic and renal 5'-deiodination of rT3 during fasting: supportive role of intermediate Mr cytosolic non-glutathione thiol cofactor and NADPH.
pubmed:affiliation
Thyroid Research Laboratory, Mount Sinai Hospital, Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't