Prostaglandin F2 alpha stimulates release of insulin-like growth factor binding protein-3 from cultured human granulosa-luteal cells.
Human ovarian follicular fluid contains a number of insulin-like growth factor binding proteins (IGFBP) of which IGFBP-3 is the most abundant. IGFBP-3 synthesis is growth hormone-regulated. We studied the effect of prostaglandin F2 alpha (PGF2 alpha) on IGFBP-3 secretion by cultured human granulosa-luteal cells from follicular aspirates of women participating in an in-vitro fertilization programme. The IGFBP-3 concentration was measured using a specific monoclonal immunofluorimetric assay. Contrary to a previous report on unstimulated follicles, this study demonstrated a positive correlation between follicular fluid IGFBP-3 concentration and follicular size. PGF2 alpha was found to stimulate in a dose-dependent fashion the secretion of IGFBP-3. Significant (P < 0.05) effects were found at PGF2 alpha concentrations of 10(-8), 10(-7) and 10(-6) M. Because IGFBP-3 inhibits progesterone production stimulated by insulin-like growth factor (IGF)-I, the PGF2 alpha-induced stimulation of IGFBP-3 production may be one of the mechanisms whereby PGF2 alpha exerts its luteolytic effect via the IGF system.
Sarvas
K
K
Department I of Obstetrics and Gynaecology, Helsinki University Central Hospital, Finland.
Angervo
M
M
Koistinen
R
R
Tiitinen
A
A
Seppälä
M
M
D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D015237:Dinoprost / Q000494:pharmacology*; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008184:Luteal Cells / Q000187:drug effects* / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D006080:Ovarian Follicle / Q000033:anatomy & histology; D011374:Progesterone / Q000096:biosynthesis; D013002:Somatomedins / Q000378:metabolism
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D011374:Progesterone; D007334:Insulin-Like Growth Factor I; D008715:Methionine; D015237:Dinoprost