Glycolytic pathway activity: effect on in vitro maturation and oxidative metabolism of bovine oocyte

CYNTHIA GUTNISKY; SERGIO MORADO; GABRIEL DALVIT; JEREMY THOMPSON; PABLO CETICA

REPRODUCTION FERTILITY AND DEVELOPMENT

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2012 vol. 25 p. 1026 - 1035

1031-3613

The aim of this study was to determine the influence of altering glycolytic pathway activity during bovine IVM on the meiotic maturation rate, oxidative activity, mitochondrial activity, and the mitochondrial distribution within oocytes. Glycolytic activity was manipulated using two inhibitors (ATP, NaF) and a stimulator (AMP) of key enzymes of the pathway. Inhibition of glucose uptake, lactate production and meiotic maturation rates was observed when media was supplemented with ATP or NaF. The addition of AMP in the maturation medium had no effect on glucose uptake, lactate production and meiotic maturation. However, in the absence of gonadotrophin supplementation, AMP stimulated both glucose uptake and lactate production. However, AMP also decreased cytoplasmic maturation, as determined by early cleavage. During IVM, oocyte oxidative and mitochondrial activity was observed to increase at 15 and 22 h of maturation. Inhibiting glycolysis with ATP or NaF led to a reduced oxidative and mitochondrial pattern compared with their respective control groups. Stimulation of the pathway with AMP increased oxidative and mitochondrial activity. A progressive mitochondrial migration to the central area was observed during maturation; oocytes treated with ATP, NaF or AMP showed limited migration. This study reveals the impact of altering the glycolytic pathway activity in COCs, revealing the link between glycolysis of the COC and oxidative and mitochondrial activity of the oocyte.