Linked Life Data

1696882

Source:http://linkedlifedata.com/resource/pubmed/id/1696882

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-9-21
pubmed:abstractText
Serum concentrations of insulin-like growth factor-I (IGF-I) in rats are reduced dramatically in the latter half of pregnancy, decreasing from 1758 +/- 356 ng/ml at 12 days of pregnancy (mean +/- SD) to 761 +/- 192 ng/ml at 15 days. After parturition, IGF-I increases to nonpregnant values in 4 days. Using ligand blotting, we have demonstrated that most of the serum IGF binding proteins (IGFBPs) are concurrently reduced during pregnancy. IGFBP-3, the predominant IGFBP in nonpregnant serum, is reduced to 1.3% of nonpregnant values by 21 days of pregnancy and begins to rise within 1 h postpartum (PP). The sera of 21-day pregnant (but not nonpregnant) rats degrade IGFBP-3 in vitro, and this degradation is prevented by the protease inhibitor antipain. Decreased serum IGF-I concentrations during pregnancy, therefore, may result from reduced IGFBP-3 concentrations causing increased IGF-I clearance. In addition, steady state IGF-I mRNA and peptide levels in liver are decreased in 21-day pregnant rats (37% and 42% of 4 day PP levels, respectively), suggesting that decreased synthesis of IGF-I may also lead to lower serum IGF-I concentrations. After bolus injection, [125I]IGF-I is cleared from the serum of pregnant rats nearly 5 times faster than that of 4 day PP rats (1.21 vs. 0.25 ml/min/kg, respectively). Urinary clearance is relatively insignificant (less than 4%), and [125I]IGF-I does not cross the placenta. The intermediate distribution phase of IGF-I is slower in pregnant rats than in PP rats (t1/2 alpha, 17.1 vs. 5.4 min), whereas the terminal elimination of IGF-I is twice as fast (t1/2 beta, 228.1 vs. 106.4 min). The prolonged IGF-I distribution phase in the pregnant rats may result from decreased concentrations of 34,000 and 30,000 mol wt IGFBPs, which may transport IGF-I to tissues. The faster serum elimination half-life may result from diminished IGFBP-3, leading to greater IGF-I availability to tissues in pregnancy.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1278-86
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1696882-Animals, pubmed-meshheading:1696882-Antipain, pubmed-meshheading:1696882-Carrier Proteins, pubmed-meshheading:1696882-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:1696882-Female, pubmed-meshheading:1696882-Insulin-Like Growth Factor Binding Proteins, pubmed-meshheading:1696882-Insulin-Like Growth Factor I, pubmed-meshheading:1696882-Kinetics, pubmed-meshheading:1696882-Liver, pubmed-meshheading:1696882-Metabolic Clearance Rate, pubmed-meshheading:1696882-Molecular Weight, pubmed-meshheading:1696882-Nucleic Acid Hybridization, pubmed-meshheading:1696882-Peptide Hydrolases, pubmed-meshheading:1696882-Pregnancy, pubmed-meshheading:1696882-Pregnancy, Animal, pubmed-meshheading:1696882-RNA, Messenger, pubmed-meshheading:1696882-Rats, pubmed-meshheading:1696882-Rats, Inbred Strains, pubmed-meshheading:1696882-Somatomedins
pubmed:year
1990
pubmed:articleTitle
Regulation of serum insulin-like growth factor-I (IGF-I) and IGF binding proteins during rat pregnancy.
pubmed:affiliation
Department of Pediatrics, Schools of Medicine, University of North Carolina, Chapel Hill 27599.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't