Oocyte mitochondrial bioenergy potential and oxidative stress: within-/between-subject, in vivo versus in vitro maturation, and age-related variations in a sheep model

Mitochondrial activity in oocytes from hormonally stimulated donor sheep shows within- and betweensubject and maturation procedure- and age-related variations. Reactive oxygen species (ROS) level increases in aged oocytes. High mitochondria-ROS colocalization identifies in vivo matured oocytes.

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Nicola Antonio Martino, B.Sc., Giovanni Michele Lacalandra, D.M.V., Manuel Filioli Uranio, B.Sc., Barbara Ambruosi, Ph.D., Michele Caira, D.M.V., Fabio Silvestre, Ph.D., Flavia Pizzi, Ph.D., Salvatore Desantis, B.Sc., Gianluca Accogli, B.Sc., Maria Elena Dell’Aquila, Ph.D.

Volume 97, Issue 3 , Pages 720-728.e1



To analyze within-/between-subject, in vivo versus in vitro maturation (IVM), and age-related variations of mitochondrial (mt) bioenergy potential and oxidative status of metaphase II (MII) oocytes recovered from hormonally stimulated sheep.


Prospective study.


Academic basic research laboratory.


Ten adult ewes.


Estrus synchronization, controlled ovarian hyperstimulation (COH), ovariohysterectomy; follicular and oviductal oocyte retrieval; IVM of follicular oocytes.

Main Outcome Measure(s):

Mean ± SD, within-subject (CVw) and between-subject (CVb) variation coefficients of mt activity, intracellular reactive oxygen species (ROS) levels, and mt/ROS colocalization in sheep oocytes from young and aged donors and matured in vivo (in vivo MIIs) or in vitro (IVM MIIs).


Within- and between-subject, in vivo versus IVM, and age-related variations of mt activity were observed in MII oocytes from hormonally stimulated donor sheep. ROS levels increased significantly in oocytes from aged donors. Mt-ROS colocalization was consistently higher in in vivo MIIs compared with IVM MIIs. Oviductal energy/antioxidant ability is influenced by COH.


Oocyte energy/oxidative status is affected by within-/between-subject, in vivo versus IVM, and age-related variations. Mt/ROS colocalization is a reliable marker of in vivo MII oocytes.

Read the full text at: http://www.fertstert.org/article/S0015-0282(11)02866-4/fulltext

Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

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