Linked Life Data

9582496

Source:http://linkedlifedata.com/resource/pubmed/id/9582496

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-5-20
pubmed:abstractText
Long-Arg3-IGF-I (LR3IGF-I) is a synthetic analog of IGF-I that has much lower affinity for IGF-binding proteins than do native IGFs-I and -II. Comparisons of the effects of LR3IGF-I with those of IGFs-I and-II in in vitro and in vivo studies have proved useful in defining the functions of IGF-binding proteins. We have developed a sensitive noncompetitive nonisotopic assay of LR3IGF-I. Mouse IgG 1A7-F5-E5 binds an epitope that contains the substituted arginine3 in LR3IGF-I and was used as the solid phase antibody. The solution phase antibody was a rabbit immunoglobulin Nelson which binds to an epitope that is common to IGF-I and LR3IGF-I. The ELISA system was able to detect as little as 50 pg LR3IGF-I in 100 microliters and the native peptides IGFs-I and -II have less than 0.01% activity. Blood plasma from animals treated with pharmacologically active doses of this growth factor analog could be diluted 33.3-fold before assay, at which concentrations plasma had no significant effect on the assay. The ELISA response to LR3IGF-I was unaffected by the presence of IGF-binding proteins. The intra-assay and interassay coefficients of variation are 2.8 and 7.3% respectively. Recovery of LR3IGF-I added to blood plasma was approximately 90%. The ELISA was used to measure LR3IGF-I concentrations in plasma of cows treated with a pharmacologically active dose of this peptide and the results were compared with those obtained by a previously established LR3IGF-I RIA that requires size exclusion chromatography of plasma under acidic conditions to eliminate IGF-binding protein artefacts from the RIA. There was a positive correlation between results obtained by the two assays. The LR3IGF-I ELISA permits discrimination between the exogenous synthetic IGF-I analog and the endogenous native IGFs-I and -II in animals treated with this growth factor without the need for radioiodination of LR3IGF-I and elimination of the requirement for extraction of plasma before assay.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-0795
pubmed:author
pubmed:issnType
Print
pubmed:volume
156
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
407-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Measurement of an analog of insulin-like growth factor-I in blood plasma using a novel enzyme-linked immunosorbent assay.
pubmed:affiliation
Department of Biochemistry, University of Adelaide, Australia.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't