Gonçalves F S, Barretto L S S, Arruda R P, Perri S H V, Mingoti G Z
Department of Animal Reproduction, School of Agricultural and Veterinary Sciences, University of São Paulo State, Jaboticabal.
Reprod Domest Anim. 2010 Feb;45(1):129-35. doi: 10.1111/j.1439-0531.2008.01272.x. Epub 2008 Oct 16.
Increased amounts of reactive oxygen species (ROS) during in vitro fertilization (IVF) may cause cytotoxic damage to gametes, whereas small amounts of ROS favour sperm capacitation. The aim of this study was to investigate the effect of antioxidants [50 microm beta-mercaptoethanol (beta-ME) and 50 microm cysteamine (Cyst)] or a pro-oxidant (5 mm buthionine sulfoximine) on the quality and penetrability of spermatozoa into bovine oocytes and on the subsequent embryo development and quality when added during IVF. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes, and mitochondrial function, was diminished (p < 0.05) after 4-h culture in the presence of antioxidants. Oocyte penetration rates were similar between treatments (p > 0.05), but antioxidants adversely affected the normal pronuclear formation rates (p < 0.05). The incidence of polyspermy was high for beta-ME (p < 0.05). No differences were observed in cleavage rates between treatments (p > 0.05). However, the developmental rate to the blastocyst stage was adversely affected by Cyst treatment (p < 0.05). The quality of embryos that reached the blastocyst stage, evaluated by total, inner cell mass (ICM) and trophectoderm cell numbers and ICM/total cell ratio was unaffected (p > 0.05) by treatments. The results indicate that ROS play a role in the fertilizing capacity in bovine spermatozoa, as well as in the interaction between the spermatozoa and the oocytes. It can be concluded that supplementation with antioxidants during IVF procedures impairs sperm quality, normal pronuclear formation and embryo development to the blastocyst stage.
体外受精（IVF）过程中活性氧（ROS）含量增加可能会对配子造成细胞毒性损伤，而少量的ROS则有利于精子获能。本研究的目的是探讨抗氧化剂[50微摩尔β-巯基乙醇（β-ME）和50微摩尔半胱胺（Cyst）]或促氧化剂（5毫摩尔丁硫氨酸亚砜胺）在IVF过程中添加时对精子质量、精子穿透牛卵母细胞的能力以及随后胚胎发育和质量的影响。在抗氧化剂存在下培养4小时后，通过质膜和顶体膜的完整性以及线粒体功能评估的精子质量下降（p<0.05）。各处理组之间的卵母细胞穿透率相似（p>0.05），但抗氧化剂对正常原核形成率有不利影响（p<0.05）。β-ME处理的多精受精发生率较高（p<0.05）。各处理组之间在卵裂率上未观察到差异（p>0.05）。然而，Cyst处理对囊胚阶段发育率有不利影响（p<0.05）。通过总细胞数、内细胞团（ICM）和滋养外胚层细胞数以及ICM/总细胞比评估的达到囊胚阶段的胚胎质量不受处理影响（p>0.05）。结果表明，ROS在牛精子的受精能力以及精子与卵母细胞之间的相互作用中发挥作用。可以得出结论，在IVF程序中添加抗氧化剂会损害精子质量、正常原核形成以及胚胎向囊胚阶段的发育。
