INVESTIGADORES
ALVAREZ Gabriel MartÍn
artículos
Título:
Phosphofructokinase and Malate Dehydrogenase Participate in the In Vitro Maturation of Porcine Oocytes
Autor/es:
ELIZABETH BREININGER; BRUNO VECCHI GALENDA; GABRIEL MARTIN ALVAREZ; CYNTHIA GUTNISKY; PABLO DANIEL CETICA
Revista:
REPRODUCTION IN DOMESTIC ANIMALS (1990)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2014 vol. 49 p. 1068 - 1073
ISSN:
0936-6768
Resumen:
Oocyte maturation depends on the metabolic activity of
cumulus?oocyte complex (COC) that performs nutritive and
regulatory functions during this process. In this work, the
enzymes [phosphofructokinase (PFK) and malate dehydrogenase
(MDH)] were tested to elucidate the metabolic profile of
porcine COCs during the in vitro maturation (IVM). Enzymatic
activity was expressed in U/COC and U/mg protein
(specific activity) as mean SEM. In vitro maturation was
performed with 2-oxoglutarate (5, 10 and 20 mM) or hydroxymalonate
(30, 60 and 100 mM) inhibitors of PFK and MDH,
respectively. The PFK and MDH activities (U) remained
constant during maturation. For PFK, the U were
(2.48 0.23) 10
5 and (2.54 0.32) 10
5, and for MDH,
the U were (4.72 0.42) 10
5 and (4.38 0.25) 10
5 for
immature and in vitro matured COCs, respectively. The
specific activities were significantly lower after IVM, for
PFK (4.29 0.48) 10
3 and (0.94 0.12) 10
3, and for
MDH (9.08 0.93) 10
3 and (1.89 0.10) 10
3 for immature
and in vitro matured COCs, respectively. In vitro maturation
percentages and enzymatic activity diminished with 20 mM
2-oxoglutarate or 60 mM hydroxymalonate (p < 0.05). Viability
was not affected by any concentration of the inhibitors
evaluated. The U remained unchanged during IVM; however,
the increase in the total protein content per COC provoked a
decrease in the specific activity of both enzymes. Phosphofructokinase
and MDH necessary for oocyte IVM would be
already present in the immature oocyte. The presence of
inhibitors of these enzymes impairs the meiotic maturation.
Therefore, the participation of these enzymes in the energy
metabolism of the porcine oocyte during IVM is confirmed in
this study.