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Modulation of Glycolysis and the Pentose Phosphate Pathway Influences Porcine Oocyte In Vitro Maturation
Author(s) -
Alvarez GM,
Ferretti EL,
Gutnisky C,
Dalvit GC,
Cetica PD
Publication year - 2013
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12123
Subject(s) - pentose phosphate pathway , glycolysis , oocyte , in vitro maturation , chemistry , medicine , endocrinology , in vitro , biology , metabolism , andrology , biochemistry , microbiology and biotechnology , embryo
Contents Glycolytic and pentose phosphate pathway ( PPP ) activities were modulated in porcine cumulus–oocyte complexes ( COC s) during in vitro maturation ( IVM ) by the addition of inhibitors or stimulators of key enzymes of the pathways to elucidate their relative participation in oocyte maturation. The activities of glycolysis and PPP were evaluated by lactate production per COC and by the brilliant cresyl blue test, respectively. Glucose uptake per COC and the oocyte maturation rate were also evaluated. Lactate production, glucose uptake and the percentage of oocytes reaching metaphase II decreased in a dose‐dependent manner in the presence of the pharmacological (NaF) or the physiological ( ATP ) inhibitors of glycolysis (p < 0.05). The addition of the physiological stimulator of glycolysis ( AMP ) caused no effect on lactate production, glucose uptake or the meiotic maturation rate. The pharmacological (6‐ AN ) and the physiological ( NADPH ) inhibitors of PPP induced a dose‐dependent decrease in the percentage of oocytes with high PPP activity and in the nuclear maturation rate (p < 0.05). The physiological stimulator of PPP ( NADP ) caused no effect on the percentage of oocytes with high PPP activity. The glycolytic and PPP activities of porcine COC s and maturational competence of oocytes seem to be closely related events. This study shows for the first time the regulatory effect of ATP and NADPH as physiological inhibitors of glycolysis and PPP in porcine COC s, respectively. Besides, these pathways seem to reach their maximum activities in porcine COC s during IVM because no further increases were achieved by the presence of AMP or NADP .