Metabolic control during preimplantation mammalian development
Metabolic control during preimplantation mammalian development
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DOI：
10.1093/humupd/1.1.63
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发表时间：
1995-01-01
影响因子：
13.3
通讯作者：
Leese, HJ
中科院分区：
文献类型：
--
作者：
Leese, HJ
着床前发育过程中的代谢控制可能是胚胎内在的，也可能是外在的，即通过雌性生殖道内的环境介导的。内在控制表现为早期植入前胚胎，其未分化，基本上是自主的，并且不显示生长。最具特征的内在代谢控制机制是在小鼠着床前发育过程中从丙酮酸转换为葡萄糖作为主要的能量底物。在后期植入前阶段，当分化成滋养外胚层和内细胞团时，开始净生长，胚胎为植入做准备。因此，由输卵管提供的环境（大多数哺乳动物物种的胚胎在其中度过它们的前3天）可以被认为是促进早期胚胎发育的而不是强制性的，而子宫环境需要提供更复杂的环境。输卵管提供的“促进剂”包括物理因素，如纤毛和肌肉作用，以及化学因素，包括氧气、营养物质、离子和大分子。输卵管液分泌受肾上腺素能影响，其缺陷可能导致女性粘膜防御受损和输卵管阻塞。植入前胚胎表现出代谢适应性，其代谢对外部环境的变化做出反应。这种适应性解释了早期胚胎在各种培养基中发育的能力，这种情况类似于它们在雌性管道中的经历。因此，在体外提供各种培养基可能确保胚胎以生理方式发育。
Metabolic control during preimplantation development may be either intrinsic to the embryo or extrinsic, i.e. mediated via the environment within the female tract. Intrinsic control is exhibited by early preimplantation embryos, which are undifferentiated, largely autonomous and show no growth. The best characterized intrinsic metabolic control mechanism is the switch from pyruvate to glucose as major energy substrate during mouse preimplantation development. A shift to extrinsic control occurs during the later preimplantation stages, when differentiation into trophectoderm and inner cell mass occurs, net growth begins and the embryo prepares for implantation. Thus, the environment provided by the oviduct, in which the embryos of most mammalian species spend their first 3 days, may be considered as facilitatory rather than obligatory for early embryo development, whereas the uterine environment is required to provide a more complex milieu. The 'facilitators' provided by the oviduct include physical factors, such as ciliary and muscular action, and chemical factors, including oxygen, nutrients, ions and macromolecules. Oviduct fluid secretion is under adrenergic influence, defects in which could contribute to impaired mucosal defence and tubal blockage in women. Preimplantation embryos exhibit metabolic adaptation, whereby their metabolism responds to changes in the external environment. Such adaptation explains the ability of early embryos to develop in a variety of culture media, a situation similar to that which they will experience in the female tract. Thus, the provision of a variety of media in vitro is likely to ensure the development of embryos in a physiological manner.