Department of Anatomy, Sapienza University, Rome 00161, Italy.
Reprod Biomed Online. 2009;19 Suppl 3:17-27. doi: 10.1016/s1472-6483(10)60280-5.
This study describes and compares the possible effects of vitrification on the ultrastructural morphology of 20 human mature oocytes vitrified using two different supports, cryoleaf (n = 10) and cryoloop (n = 10). Fresh human mature oocytes (n = 15) were used as controls. Fresh and vitrified-warmed oocytes appeared rounded, with a homogeneous cytoplasm, an intact oolemma and a continuous zona pellucida. Sparse microvacuolization was only occasionally detected in fresh and vitrified-warmed oocytes, to the same extent. About 50% of the vitrified oocytes contained atypical, small and slender mitochondria-smooth endoplasmic reticulum aggregates, whereas a non-homogeneous microvillar pattern was observable in only 30% of the oocytes subjected to vitrification, regardless of the support utilized. Cortical granule content appeared generally reduced after vitrification, but cryoleaf-supported oocytes contained more cortical granules than cryoloop-supported oocytes (P < 0.05). Thus good overall preservation and virtual absence of cytoplasmic vacuolization seem to be the most relevant markers of quality in vitrified-warmed oocytes, using either support. In addition, cryoleaf-supported oocytes retained a higher number of cortical granules than cryoloop-supported oocytes. The variety of ultrastructural alterations recorded emphasizes the need for further studies aimed at assessing the actual tolerance of human oocytes to vitrification.
本研究描述并比较了两种不同载体（ cryoleaf 和 cryoloop ）对 20 个人类成熟卵母细胞玻璃化超微结构形态的可能影响。新鲜人类成熟卵母细胞（n = 15）用作对照。新鲜和玻璃化温育的卵母细胞呈圆形，细胞质均匀，卵母细胞透明带完整且连续。新鲜和玻璃化温育的卵母细胞中偶尔会发现稀疏的微空泡化，程度相同。大约 50%的玻璃化卵母细胞含有异常的小而细长的线粒体-光滑内质网聚集物，而只有 30%的卵母细胞发生玻璃化时会观察到非均匀的微绒毛模式，无论使用哪种载体。皮质颗粒含量在玻璃化后通常会减少，但 cryoleaf 支持的卵母细胞比 cryoloop 支持的卵母细胞含有更多的皮质颗粒（P < 0.05）。因此，使用任何一种载体，玻璃化温育的卵母细胞中良好的整体保存和几乎不存在细胞质空泡化似乎是质量的最相关标志物。此外，cryoleaf 支持的卵母细胞比 cryoloop 支持的卵母细胞保留了更多的皮质颗粒。记录的各种超微结构改变强调需要进一步研究，以评估人类卵母细胞对玻璃化的实际耐受性。
