Glucose metabolism in the trophectoderm and inner cell mass of the rabbit embryo.
The metabolism of glucose in the intact Day-6 and -7 post coitum (p.c.) rabbit blastocyst and in the separated trophectoderm and inner cell mass (ICM) of the Day-7 p.c. embryo was investigated. At Day-6 p.c., glucose traversed the trophectoderm with a half-time of 39 +/- 9.3 min, and was metabolized to CO2 at a rate of 25.5 +/- 1.6 nmol.cm-2.h-1. Neither the Na+ ionophore, amphotericin B, nor cyclic AMP had an effect on glucose metabolism to CO2. Lactate production by the Day-6 blastocyst was largely independent of glucose. At Day-7 p.c. in the intact embryo, CO2 production from glucose significantly decreased to 7.76 +/- 2.8 nmol.cm-2.h-1. Per unit surface area, the metabolism of glucose to CO2 was similar in the separated Day-7 p.c. trophectoderm and ICM. We conclude that the rabbit blastocyst is not highly dependent on glucose, and that the ICM does not utilize glucose as a metabolite to a greater extent than does the trophectoderm, at least in the Day-7 p.c. embryo.
Robinson
D H
DH
Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
Benos
D J
DJ
D000818:Animals; D001755:Blastocyst / Q000378:metabolism* / Q000502:physiology; D002245:Carbon Dioxide / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D011817:Rabbits
D007773:Lactates; D002245:Carbon Dioxide; D019344:Lactic Acid; D005947:Glucose