Effects of culture media and energy sources on the inhibition of nuclear maturation in bovine oocytes.
The influence of the culture medium and energy sources on spontaneous nuclear maturation and inhibition of maturation in bovine cumulus-enclosed oocytes (CEO) was examined. CEO were cultured in Medium 199, minimum essential medium, M16, or synthetic oviduct fluid (SOF), all containing 3 mg/mL bovine serum albumin (BSA), and SOF without BSA, alone or supplemented with hypoxanthine (HYPO, 4 mM) or forskolin (FSK, 100 microM) for 21 h. More CEO remained at the GV stage in M16 compared to other media (P < 0.05). Supplementation with HYPO increased and FSK reduced the percentage of CEO remaining at the GV stage (P < 0.05) only in M16. The effects of energy sources, in the absence or presence of HYPO or FSK, were examined in CEO cultured in M16 salts+PVA. Glucose (0.5 and 5.5 mM), pyruvate (0.32 and 3.2 mM), lactate (3.3 mM) and glutamine (1.3 mM) significantly reduced the percentage of CEO remaining at the GV stage compared to M16 salts alone; only glutamine significantly increased the percentage of CEO at the MII stage compared to M16 salts. In M16 salts+HYPO, glucose (0.5 mM), pyruvate (0.32 mM), lactate (3.3 mM) and glutamine (1.3 mM) significantly reduced the percentage of GV and degenerate oocytes and increased the percentage of CEO at the MI stage. In M16 salts+FSK, the energy sources significantly decreased the percentage of oocytes with condensed chromosomes and increased the percentage of CEO reaching metaphase I. In conclusion, meiotic inhibitors had different effects in different culture media and glucose, pyruvate, lactate and glutamine were stimulatory to nuclear maturation. It was noteworthy that some of the results obtained were contrary to previous findings in mouse oocytes.
Bilodeau-Goeseels
Sylvie
S
Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1st Ave. South, P.O. Box 3000, Lethbridge, Alta., Canada T1J 4B1. goeseelss@agr.gc.ca
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D005576:Colforsin / Q000378:metabolism / Q000494:pharmacology*; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D019271:Hypoxanthine / Q000378:metabolism / Q000494:pharmacology*; D019344:Lactic Acid / Q000378:metabolism; D008540:Meiosis / Q000187:drug effects* / Q000502:physiology*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D019289:Pyruvic Acid / Q000378:metabolism; D013045:Species Specificity
D003470:Culture Media; D005973:Glutamine; D005576:Colforsin; D019271:Hypoxanthine; D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose