Nakano Mayu, Kato Yoko, Tsunoda Yukio
Laboratory of Animal Reproduction, College of Agriculture, Kinki University, Nara, 631-8505, Japan.
Zygote. 2012 May;20(2):199-207. doi: 10.1017/S0967199411000190. Epub 2011 Jul 1.
Melatonin secreted from the mammalian pineal gland is a free-radical scavenger that protects tissues from cell damage. The present study examined the effects of addition of melatonin to the culture medium on the developmental potential of parthenogenetic and somatic cell nuclear-transferred (SCNT) porcine oocytes. Supplementation of the maturation medium with melatonin did not increase the maturation rate, the proportion of oocytes that cleaved and developed into blastocysts after parthenogenetic activation, or the blastocyst cell number compared to controls. When 10-7 M melatonin was added to the culture medium, the proportion of parthenogenetic oocytes that developed to the 2-cell and 4-cell stages was significantly higher than that of controls. The potential of melatonin-treated oocytes to develop into blastocysts was high but not significantly different from that of controls. The addition of 10-7 M melatonin to the culture medium did not increase the preimplantation development of SCNT oocytes. Melatonin treatment significantly reduced the levels of reactive oxygen species in 4-cell parthenogenetic and SCNT embryos, but did not reduce the proportion of apoptotic cells in parthenogenetic and SCNT blastocysts. Although the results indicated that parthenogenetic and SCNT melatonin -treated embryos had significantly lower levels of reactive oxygen species than controls, the potential of melatonin-treated embryos to develop into blastocysts was not significantly higher than that of controls, in contrast to previous reports. The beneficial effects of melatonin on the developmental potential of oocytes might depend on the culture conditions.
哺乳动物松果体分泌的褪黑素是一种自由基清除剂，可保护组织免受细胞损伤。本研究检测了在培养基中添加褪黑素对孤雌生殖和体细胞核移植（SCNT）猪卵母细胞发育潜力的影响。与对照组相比，在成熟培养基中添加褪黑素并未提高孤雌生殖激活后卵母细胞的成熟率、卵裂并发育成囊胚的比例或囊胚细胞数量。当向培养基中添加10-7 M褪黑素时，发育到2细胞和4细胞阶段的孤雌生殖卵母细胞比例显著高于对照组。经褪黑素处理的卵母细胞发育成囊胚的潜力较高，但与对照组无显著差异。向培养基中添加10-7 M褪黑素并未提高SCNT卵母细胞的植入前发育。褪黑素处理显著降低了4细胞孤雌生殖和SCNT胚胎中的活性氧水平，但并未降低孤雌生殖和SCNT囊胚中的凋亡细胞比例。尽管结果表明，与对照组相比，经褪黑素处理的孤雌生殖和SCNT胚胎中的活性氧水平显著降低，但与之前的报道相反，经褪黑素处理的胚胎发育成囊胚的潜力并不显著高于对照组。褪黑素对卵母细胞发育潜力的有益影响可能取决于培养条件。
