title: Assessment of metabolism of equine morulae and blastocysts.
abstract: Nutrient uptakes and metabolite production by equine morula and blastocyst stage embryos were determined by non-invasive microfluorometry. Equine morula took up equal amounts of both pyruvate and glucose. However, at the early blastocyst there was a small increase in glucose uptake and, by the expanded blastocyst stage, glucose was the predominant nutrient. Expanded blastocysts took up five times more glucose than pyruvate. Expanded blastocysts exhibited an exponential increase in glucose uptake and lactate production with respect to both diameter and surface area. As less than 50% of the glucose was accounted for by lactate production, the equine blastocyst appears to have a significant capacity to oxidize glucose. Embryos with a higher morphological grade consumed more nutrients than those with a poorer morphology. However, there was a large range in nutrient consumption within the highest grade blastocysts. This suggests that nutrient uptake may be useful as a viability marker of equine blastocysts.
authors.affiliation: Colorado Center for Reproductive Medicine, Englewood, Colorado 80110, USA. mlane@colocrm.com
authors.forename: M
authors.initials: M
authors.lastname: Lane
authors.forename: M K
authors.initials: MK
authors.lastname: O'Donovan
authors.forename: E L
authors.initials: EL
authors.lastname: Squires
authors.forename: G E
authors.initials: GE
authors.lastname: Seidel
authors.forename: D K
authors.initials: DK
authors.lastname: Gardner
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism*; D048429:Cell Size; D003592:Cytophotometry; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006736:Horses / Q000196:embryology* / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D009028:Morula / Q000166:cytology / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose