For evaluating the suitability of human follicular fluid (HFF) as protein supplement in ART, this preliminary study was performed to examine the maturation promoting activity of HFF on mouse follicular oocytes in vitro. Mouse follicular oocytes
were
collected from ovaries of 21-28 day old ICR mice by puncturing the antral follicle with fine needle at 48 hours after PMSG injection. The oocytes were rinsed and cultured in modified Whittingham's T6 medium containing purines or dbcAMP to
maintain
meiotic arrest, and different concentrations of HFF were added into the culture medium to examine the effect of HFF on releasing the oocytes from the suppressive influence of the meiotic inhibitors. As a control for HFF, the maturation promoting
activity of human fetal cord serum (HFCS) was investigated and compared with the activity of HFF. While HFF was separated, by molecular weight (M.W), into high M.W. fraction (M.W>30,000) and low M.W. fraction (M.W<30,000) and the effects of the
fractions on meiotic resumption were investigated in the presence of the meiotic inhibitors. Also hormone analysis was performed to compare the content of hormones in HFF with that in HFCS. Same concentrations of HFF and HFCS induced similar
germinal
vesicle break down (GVBD) rates of oocytes meiotic arrested by purines (4mM hypoxanthine+0.75mM adenosine), but the extrusion rate of 1st polar body (PB) of the oocytes cultured in HFF (65.0%, P<0.05) was significantly higher than that (51.6%) in
HFCS.
While, in the presence of 200 M dbcAMP, the maturation promoting activity of HFF (GVBD: 70.5%, p<10E-6, 1st PB extrusion: 67.1%, p<10E-3) was significantly greater than that of HFCS (GVBD: 35.2%; 1st PB extrusion: 41.1%). The oocytes cultured in
the
fraction of HFF containing high M.W. components showed higher meiotic maturation rates than the ooyctes cultured in the low M.W. fraction of HFF. Gonadotropins and E2 were known to improve the completion of maturation changes, and the levels of
these
hormones were higher in HFF than in HFCS. Therefore, HFF was more effective than HFCS o use for promoting meiotic resumption of mouse oocytes in vitro.
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