The bovine placenta: a specific radioreceptor assay for both insulin-like growth factor I and insulin-like growth factor II.
Acta Endocrinol (Copenh)
; 118(2): 306-13, 1988 Jun.
Article
em En
| MEDLINE
| ID: mdl-2968751
ABSTRACT
Binding of labelled IGF-I and IGF-II was studied to bovine, ovine and human placental cell membranes. The data show a preponderance of type I receptors in human placental membranes, and of type II receptors in ovine placental membranes, confirming reported data. In contrast, bovine placental membranes are rich in both type I and type II receptors. Therefore, the bovine placenta offers a good model for measuring specifically IGF-I (cross-reactivity with IGF-II 7%) and IGF-II (cross-reactivity with IGF-I 4%). By Scatchard analysis the apparent Kd (1-1.36 nmol/l) for the high affinity binding sites of the type I receptor is similar in all three preparations. Total binding capacity in ovine placental membranes is, however, 4 times lower. The affinity for the type II receptor is lower than for type I, whereas total binding capacity is higher. Affinity cross-linking confirms the competition experiments, showing binding of IGF-I to typical type I and of IGF-II to type II receptors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Female
/
Humans
Idioma:
En
Ano de publicação:
1988
Tipo de documento:
Article