Linked Life Data

1267008

Source:http://linkedlifedata.com/resource/pubmed/id/1267008

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1976-7-6
pubmed:abstractText
Sephadex G-100 chromatography of rat liver supernatant after addition of [125I]T3 revealed four peaks of protein-bound radioactivity in the void volume, albumin, ligandin, and Z-containing regions, respectively. The peaks were identified by cochromatography of BSP and [125I]T3 and immonodiffusion with antiratligandin IgG and antirat Z IgG. Binding of [125I]T4 to rat liver supernatant occurred in void volume, albumin, and Z regions only. Studies in vivo reveal a pattern of [125I]T3 binding to rat liver supernatant fractions quantitatively different from that observed in vitro. [125I]T4 binding to liver supernatant fractions in vivo occurred in all four peaks. BSP or bilirubin added to liver supernatant decreased T3 and T4 binding by each fraction. Flavaspidic acid inhibited binding of T3 and T4 to albumin, ligandin, and Z protein. Phenobarbital pretreatment of rats increased binding of T3 by ligandin and of T4 by albumin-containing fractions. Circular dichroism studies with purified rat liver ligandin suggest that T3 and T4 bind competitively to the same site as does bilirubin; the association constants of T3 and T4 for ligandin are 10(6) and 10(5) M-1, respectively. T4 was bound only by purified ligandin and not by ligandin in liver supernatant. To determine whether unconjugated bilirubin interferes with hepatic uptake of T3, [125I]T3 was administered to icteric homozygous and phenotypically normal heterozygous Gunn rats. Hepatic uptake and supernatant binding [125I]T3 were significantly reduced in homozygous Gunn rats. Hepatic uptake of [125I]T3 was also reduced in vivo by infusion of BSP with or without flavaspidic acid. BSP infusion abolished [125I]T3 binding to ligandin; BSP and flavaspidic acid abolished binding to ligandin and Z. These observations suggest that ligandin and Z protein are thyroid hormone binding proteins in rat liver cytosol and may influence the net flux of iodothyronies from plasma into the liver.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
230
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1113-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Ligandin and Z protein in binding of thyroid hormones by the liver.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, U.S. Gov't, P.H.S.