Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China.
Theriogenology. 2011 Sep 15;76(5):785-93. doi: 10.1016/j.theriogenology.2011.04.011. Epub 2011 Jun 25.
The objective was to determine whether adding L-carnitine in IVM/IVC medium enhanced maturation and developmental competence of porcine oocytes in vitro. Oocyte maturation rates did not differ significantly among groups supplemented with 0, 0.25, 0.5, or 1 mg/mL of L-carnitine added during IVM (although 2 mg/mL of L-carnitine reduced maturation rate). Compared with control oocytes, those treated with 0.5 mg/mL of L-carnitine during IVM had greater (P < 0.05) rates of blastocyst formation after parthenogenetic activation, and these blastocysts had less (P < 0.05) apoptosis. Adding 0.5 mg/mL of L-carnitine during IVM also significantly reduced intracellular reactive oxygen species (ROS), and increased glutathione (GSH) concentrations. With or without glucose supplementation, 0.5 mg/mL of L-carnitine in the IVM medium significantly hastened nuclear maturation of oocytes. Moreover, supplementing the IVM medium with either glucose or L-carnitine increased (P < 0.05) percentages of oocytes that reached the metaphase II (MII) stage, relative to a control group. Final maturation rates in IVM medium containing either glucose or L-carnitine were not significantly different. Adding L-carnitine (0 to 2 mg/mL) to IVC medium for activated porcine oocytes did not significantly affect development. However, 0.5 mg/mL of L-carnitine in IVC medium significantly reduced reactive oxygen species levels and apoptosis in activated blastocysts, although glutathione concentrations were not significantly altered. In conclusion, adding L-carnitine during IVM/IVC improved developmental potential of porcine oocytes, and also the quality of parthenogenetic embryos, probably by accelerating nuclear maturation, and preventing oxidative damage and apoptosis.
目的是确定在 IVM/IVC 培养基中添加 L-肉碱是否能提高猪卵母细胞的体外成熟和发育能力。添加 0、0.25、0.5 或 1mg/ml L-肉碱的 IVM 组卵母细胞成熟率无显著差异（尽管 2mg/ml L-肉碱降低了成熟率）。与对照组卵母细胞相比，经 0.5mg/ml L-肉碱处理的卵母细胞在孤雌激活后形成囊胚的比率更高（P＜0.05），且这些囊胚的凋亡率更低（P＜0.05）。在 IVM 中添加 0.5mg/ml L-肉碱还显著降低了细胞内活性氧（ROS）的水平，增加了谷胱甘肽（GSH）的浓度。无论是否添加葡萄糖，IVM 培养基中添加 0.5mg/ml L-肉碱均可显著加快卵母细胞的核成熟。此外，与对照组相比，在 IVM 培养基中添加葡萄糖或 L-肉碱均可增加（P＜0.05）达到中期 II（MII）阶段的卵母细胞比例。含有葡萄糖或 L-肉碱的 IVM 培养基中的最终成熟率无显著差异。在激活的猪卵母细胞的 IVC 培养基中添加 L-肉碱（0 至 2mg/ml）对发育没有显著影响。然而，IVC 培养基中添加 0.5mg/ml L-肉碱可显著降低激活囊胚中的活性氧水平和凋亡率，尽管谷胱甘肽浓度没有显著改变。总之，在 IVM/IVC 期间添加 L-肉碱可提高猪卵母细胞的发育潜能，还可提高孤雌胚胎的质量，可能是通过加速核成熟，防止氧化损伤和凋亡来实现的。
