title: Glycolytic pathway activity: effect on IVM and oxidative metabolism of bovine oocytes.
abstract: The aim of the present study was to determine the effect 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 were supplemented with ATP or NaF. The addition of AMP to the maturation medium had no effect on glucose uptake, lactate production or meiotic maturation. 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 22h maturation. Inhibiting glycolysis with ATP or NaF led to a reduced oxidative and mitochondrial pattern compared with the 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. The present study reveals the effects of altering glycolytic pathway activity in cumulus-oocyte complexes, revealing the link between glycolysis of the cumulus-oocyte complex and the oxidative and mitochondrial activity of the oocyte.
authors.affiliation: Institute of Research and Technology on Animal Reproduction, School of Veterinary Sciences, University of Buenos Aires, Chorroarín 280, Buenos Aires C1427CWO, Argentina. cgutnisky@fvet.uba.ar
authors.forename: Cynthia
authors.initials: C
authors.lastname: Gutnisky
authors.forename: Sergio
authors.initials: S
authors.lastname: Morado
authors.forename: Gabriel C
authors.initials: GC
authors.lastname: Dalvit
authors.forename: Jeremy G
authors.initials: JG
authors.lastname: Thompson
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Cetica
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects / Q000502:physiology*; D059471:In Vitro Oocyte Maturation Techniques; D019344:Lactic Acid / Q000096:biosynthesis; D008540:Meiosis / Q000502:physiology; D008928:Mitochondria / Q000502:physiology; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D012969:Sodium Fluoride / Q000494:pharmacology
chemical_list: D019344:Lactic Acid; D000255:Adenosine Triphosphate; D012969:Sodium Fluoride; D005947:Glucose