The expression of glucose transporters 1, 2, 3 and 4 was evaluated in human oocytes and polyploid preimplantation embryos. Only glucose transporter 1 (GLUT-1) isoform was detected in oocytes and in 2-12-cell stage embryos. Glucose uptake was markedly increased in embryos as compared to oocytes (19.7 +/- 3.4 pmol/min/embryo and 2.3 +/- 0.3 pmol/min/oocyte), and GLUT-1 was inhibited by cytochalas...

There is increasing evidence that even before implantation, human development is regulated by embryonically and maternally derived growth factors. Studies in other mammalian species have shown that growth factors and their receptors are expressed by the preimplantation embryo and the reproductive tract. Furthermore, a number of growth factors have been shown to affect rate of embryo development...