[Use of different oxidation substrates in the energy metabolism of mammalian germ cells and embryos].

Mammalian oocytes and embryos on the early stages of development are in need of pyruvate as source of energy. The pyruvate or pyruvate and lactate combination are necessary for the processes of the maturation and fertilisation. The 8-cell stage embryos tend to change their energetical metabolism. The mouse embryos at this stage of development begin to utilise the glucose. alpha-Ketoglutarate without pyruvate, lactate or glucose is necessary for the development of cow and pig embryos after 8-cell stage.