Human granulosa cells synthesize low molecular weight insulin-like growth factor-binding protein.
Human follicular fluid contains insulin-like growth factor I (IGF-I) and its low molecular weight binding protein (IGF-BP). We studied the synthesis of IGF-BP by the granulosa cells obtained after ovarian hyperstimulation for in vitro fertilization. The granulosa cells were cultured for 72 hours in Ham's F-10 medium supplemented with 10% fetal calf serum (FCS). Samples of the culture medium were collected every 24 hours. The IGF-BP concentration in culture medium increased from 1.2 to 2.1 micrograms/l at 48 h and to 3.3 micrograms/l at 72 h. De novo synthesis of IGF-BP was shown by incorporation of labeled methionine into immunoreactive IGF-BP, as detected by SDS polyacrylamide electrophoresis (PAGE) and fluorography. Our results demonstrate synthesis of IGF-BP in the human ovary.
Suikkari
A M
AM
Department I of Obstetrics and Gynecology, University Central Hospital, Helsinki, Finland.
Jalkanen
J
J
Koistinen
R
R
Bützow
R
R
Ritvos
O
O
Ranta
T
T
Seppälä
M
M
D002478:Cells, Cultured; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000378:metabolism*
D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I