UTILIZATION OF GLUCOSE BY THE IMPLANTING MOUSE BLASTOCYST ACTIVATED BY ESTROGEN

  • 1 January 1980
    • journal article
    • research article
    • Vol. 76  (1) , 82-93
Abstract
Blastocysts from mice in an experimental delay of implantation increased their oxidation rate of glucose and fructose when implantation was initiated by an injection of estrogen. About 18 h after the injection, the rate of glucose oxidation was significantly higher than that of fructose oxidation. Simultaneously, with the increase in the rate of glucose oxidation, glycogen granules appeared in the trophoblast cells. In uterine flushings, the amount of glucose increased at 6 h. This time corresponds to the period when the blastocyst becomes activated for implantation. Determination of glucose use by the blastocysts demonstrated that 3 h after the estrogen injection, the usage was low, but that it was markedly increased at 6 and 18 h. At the initiation of implantation, mouse blastocysts prefer glucose to fructose. Presence of glucose in the secretion and the increased use of glucose by blastocysts at this time suggest that this substrate could be one important nutrient for the blastocyst at early implantation. Glucose cannot be the sole factor critical for the activation of the delayed blastocyst.