Linked Life Data

12604504

Source:http://linkedlifedata.com/resource/pubmed/id/12604504

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-5-8
pubmed:abstractText
At present, the circulating bioactivity of insulin-like growth factor I (IGF-I) is estimated by immunological measurements of IGF-I levels. However, immunoassays ignore the modifying effects of the IGF-binding proteins (IGFBPs) on the interaction between IGF-I and the IGF-I receptor (IGF-IR). Therefore, we developed an IGF-I kinase receptor activation assay (KIRA) based on cells transfected with the human IGF-IR gene. The bioassay was sensitive (detection limit 0.08 microg/l), specific (cross-reactivity of insulin, insulin analogs, and proinsulin was <1%; IGF-II cross-reactivity was 12%), and accurate (within- and between-assay coefficients of variation <7 and <15%). The operational range of the assay (0.25-10.0 microg/l) allowed for determination of IGF-I bioactivity in serum from patients with, for example, growth hormone deficiency, type 1 diabetes, and acromegaly. Addition of IGFBPs dose dependently reduced the KIRA signal, whereas addition of IGF-II to preformed complexes (1:1 molar ratio) of IGF-I and IGFBP dose dependently increased IGF-I bioactivity by displacement of bound IGF-I. In conclusion, the KIRA will enable us to compare IGF-I bioactivity with existing immunological measurements of IGF-I in serum and, hopefully, to elucidate the factors that determine IGF-I bioactivity in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0193-1849
pubmed:author
pubmed:issnType
Print
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
E1149-55
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
A highly sensitive and specific assay for determination of IGF-I bioactivity in human serum.
pubmed:affiliation
Medical Department M, Aarhus University Hospital, DK-8000 Aarhus C, Denmark. wen@iekf.au.dk
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't