SummaryThe aim of the present study was to investigate the effects of porcine follicular fluid (pFF) from large-sized (LFF; >8 mm in diameter) and medium-sized (MFF; 3–6 mm in diameter) follicles on the maturation and developmental competence of porcine oocytes. Cumulus–oocyte complexes (COCs) were collected from follicles 3–6 mm in diameter. The collected COCs were incubated for 22 h with LFF or MFF (in vitromaturation (IVM)-I stage) and were incubated subsequently for 22 h with LFF or MFF (IVM-II stage). Cumulus expansion was confirmed after the IVM-I stage and nuclear maturation was evaluated after the IVM-II stage. Intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured and embryonic development was evaluated. Relative cumulus expansion and GSH levels were higher in the LFF group compared with in the MFF group after the IVM-I stage (P <0.05). After the IVM-II stage, the numbers of oocytes in metaphase-II were increased in the LFF group and GSH content was higher in all of the LFF treatment groups compared with in the MFF treatment groups during both IVM stages (P <0.05). ROS levels were reduced by LFF treatment regardless of IVM stage (P <0.05). Blastocyst formation and the total numbers of cells in blastocysts were increased in all LFF treatment groups compared with the control group (P <0.05). These results suggested that pFF from large follicles at the IVM stage could improve nucleic and cytoplasmic maturation status and further embryonic development through reducing ROS levels and enhancing responsiveness to gonadotropins.

中文翻译：

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来自> 8 mm大小卵泡的猪卵泡液可改善猪体外成熟过程中的卵母细胞成熟和胚胎发育

摘要本研究的目的是研究来自大尺寸（LFF；直径 >8 毫米）和中型（MFF；直径 3-6 毫米）卵泡的猪卵泡液 (pFF) 对成熟和猪卵母细胞的发育能力。从直径 3-6 毫米的卵泡中收集卵丘-卵母细胞复合物 (COC)。收集的 COC 与 LFF 或 MFF 一起孵育 22 小时（体外成熟（IVM）-I 阶段）并随后与 LFF 或 MFF（IVM-II 阶段）一起孵育 22 小时。在 IVM-I 阶段后确认了积云扩张，并在 IVM-II 阶段后评估了核成熟。测量细胞内谷胱甘肽 (GSH) 和活性氧 (ROS) 水平并评估胚胎发育。在 IVM-I 期后，LFF 组的相对积云扩张和 GSH 水平高于 MFF 组（磷 <0.05)。在IVM-II期后，LFF组的中期II卵母细胞数量增加，所有LFF治疗组的GSH含量均高于MFF治疗组。磷 <0.05)。无论 IVM 分期如何，LFF 治疗都会降低 ROS 水平（磷 <0.05)。与对照组相比，所有 LFF 治疗组的囊胚形成和囊胚中的细胞总数均增加（磷 <0.05)。这些结果表明，来自 IVM 阶段大卵泡的 pFF 可以通过降低 ROS 水平和增强对促性腺激素的反应性来改善核和细胞质成熟状态并促进胚胎发育。