Immunoreactive insulin-like growth factor binding protein-3 in the culture of human luteinized granulosa cells.
Granulosa cells from human preovulatory follicles were cultured under serum-free conditions to investigate the presence of immunoreactive insulin-like growth factor binding protein-3 (IGFBP-3). IGFBP-3 levels were measured by a radioimmunoassay developed against the acid-stable subunit of the protein. The antiserum had no cross-reactivity to the low molecular weight GH-independent IGFBP-1. Granulosa luteal cells exhibited a continuous release of IGFBP-3 into the culture medium during the whole time (6 days) of the incubation. A dose-dependent increase in IGFBP-3 was observed when the cells were treated by dibutyryl cAMP. Cycloheximide suppressed almost completely both the basal and the stimulated production of IGFBP-3. The smallest effective dose of dibutyryl cAMP enhancing the progesterone release was lower than that for IGFBP-3. The different time course of IGFBP-3 and progesterone secretion to dibutyryl cAMP treatment, as well as the failure of progesterone to elicit IGFBP-3 increase alone, do not support the participation of progesterone in the IGFBP-3 production of granulosa cells. It is concluded that 1. immunoreactive IGFBP-3 is produced by cultured granulosa luteal cells; 2. its synthesis is regulated by physiological intracellular mechanisms.
Hamori
M
M
Department of Obstetrics and Gynecology, University of Tübingen, FRG.
Blum
W F
WF
Török
A
A
Stehle
R
R
Waibel
E
E
Cledon
P
P
Ranke
M B
MB
D003994:Bucladesine / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007700:Kinetics; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology; D013002:Somatomedins / Q000378:metabolism*
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D011374:Progesterone; D003994:Bucladesine; D003513:Cycloheximide