Glycosaminoglycans in porcine follicular fluid promoting viability of oocytes in culture.

The viability of oocytes cultured in vitro was determined by the trypan blue exclusion test. Isolated porcine oocytes with or without cumulus cells cultured in modified Krebs-Ringer medium undergo cell death after 48 h. The addition of glycosaminoglycans (GAGs) prepared from porcine follicular fluid (pFF) to the medium delayed or prevented the onset of cell death in vitro. GAGs at concentrations of 0.25 mg/ml or greater prevented cell death in a dose-dependent manner. To identify the active factor, GAGs were purified from pFF by ethanol precipitation, chromatography on Dowex 1-x2, and high performance liquid chromatography (HPLC) on TSK gel DEAE-2 SW column. The fraction with a retention time nearly coincident with that of hyaluronic acid possessed high oocyte viability promoting activity. The present results suggest that the viability of oocytes in vitro is influenced by the presence of specific GAGs separated from follicular fluid.