Linked Life Data

7505460

Source:http://linkedlifedata.com/resource/pubmed/id/7505460

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1994-1-27
pubmed:abstractText
Most insulin-like growth factor-I (IGF-I) in blood is found in complex with IGF binding protein-3 (IGFBP-3). An additional association of IGFBP-3 with an acid-labile subunit is thought to severely limit its ability to cross the vascular endothelium. However, it is not clear whether IGFBP-3 which is not complexed to acid-labile subunit can gain access to tissues and contribute to the transcapillary transport of IGF-I. We have investigated the concentration time profile of 125I-labelled recombinant, non-glycosylated human IGFBP-3 in the rat circulation, its appearance within various organs, urine, and in peritoneal lavage fluid. Radiolabelled IGFBP-3 was administered as a single infusion over 1 min into the catheterized jugular vein of male Wistar rats. Blood was sampled from the femoral artery, and urine by cannulation of the bladder for up to 3 h. The peritoneal cavity was cannulated to allow for the collection of lavage fluid. In a separate series of animals various organs were collected up to 3 h following administration of 125I-labelled IGFBP-3, and the content of radiolabel estimated by gamma spectrometry. Radiolabelled IGFBP-3 was rapidly cleared from the circulation initially (half-life 25 min), however from 70 min life to 3 h the levels of radiolabel remained constant. Neutral gel filtration on Sephadex G200 revealed that 1 h following administration the majority of the [125I]IGFBP-3 existed within a complex of 100-120 kDa, likely to represent an association with the acid-labile subunit. Radioactivity was detected in urine within 30 min of IGFBP-3 administration, was maximally present at 60 min, but declined thereafter. A proportion of the radiolabel in urine represented degraded protein fragments of IGFBP-3, although only 8% of the administered radiolabel was excreted within urine over 3 h. Within 10 min of entry into blood 125I-labelled IGFBP-3 was found within peritoneal lavage fluid. Most of the radiolabel was accumulated within the kidneys, liver, stomach and intestine up to 3 h after administration. However, while the hepatic and renal content were maximal after 30 min, stomach content continued to rise over 1 h, and stabilized at 15% of administered dose for up to 3 h. The results suggest that when not in complex with the acid-labile subunit, IGFBP-3 can rapidly cross capillary endothelia from blood to extravascular compartments. While kidney and liver are likely sites of excretion and degradation, a substantial proportion of IGFBP-3 is also accumulated by gastrointestinal tissues.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0167-0115
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
133-43
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Elimination of radiolabelled recombinant human insulin-like growth factor binding protein-3 from the circulation, and its distribution amongst organs and tissues in adult male rats.
pubmed:affiliation
MRC Group in Fetal and Neonatal Health and Development, Lawson Research Institute, St. Joseph's Health Centre, London, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't