title: Enhancement of lipid metabolism with L-carnitine during in vitro maturation improves nuclear maturation and cleavage ability of follicular porcine oocytes.
abstract: The aim of the present study was to assess the effects of L-carnitine, an enhancer of lipid metabolism and mitochondrial activity, during in vitro maturation (IVM) on nuclear maturation and in vitro fertilisation of porcine follicular oocytes and subsequent embryo development. Mitochondrial functions, intracellular lipid content and reactive oxygen species (ROS) levels in oocytes were also investigated. L-carnitine supplementation in 0.6-5mgmL(-1) concentration during IVM significantly improved (P<0.05) the rates of metaphase-II (MII) stage oocytes compared with the control; however, fertilisation rates and monospermy were not improved. Although supplementation of IVM medium with L-carnitine significantly increased oocyte cleavage (P<0.05), further development to the blastocyst stage was not improved. The density of active mitochondria was significantly higher and the density of lipid droplets was significantly lower (P<0.05) in L-carnitine-treated oocytes compared with the control. Furthermore, the ROS levels in L-carnitine-treated oocytes were significantly lower than those in the control. In conclusion, enhancing mitochondrial functions by L-carnitine improved oocyte maturation and cleavage underlining the importance of lipid metabolism for nuclear and cytoplasmic maturation of porcine oocytes.
authors.affiliation: National Institute of Livestock and Grassland Science, National Agriculture and Food Research Organisation, Tsukuba, Ibaraki, Japan. somfai@affrc.go.jp
authors.forename: Tamás
authors.initials: T
authors.lastname: Somfai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Akagi
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.forename: Seiki
authors.initials: S
authors.lastname: Haraguchi
authors.forename: Eiji
authors.initials: E
authors.lastname: Mizutani
authors.forename: Thanh Quang
authors.initials: TQ
authors.lastname: Dang-Nguyen
authors.forename: Masaya
authors.initials: M
authors.lastname: Geshi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology; D002331:Carnitine / Q000378:metabolism*; D002452:Cell Count / Q000662:veterinary; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism*; D055598:Chemical Phenomena; D003433:Crosses, Genetic; D054885:Cumulus Cells / Q000502:physiology; D004477:Ectogenesis; D005260:Female; D005306:Fertilization; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary*; D050356:Lipid Metabolism; D008677:Metaphase; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D009866:Oogenesis; D017382:Reactive Oxygen Species / Q000378:metabolism; D034421:Sus scrofa / Q000196:embryology / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D002331:Carnitine