Lc. Hewitson et Hj. Leese, ENERGY-METABOLISM OF THE TROPHECTODERM AND INNER CELL MASS OF THE MOUSE BLASTOCYST, The Journal of experimental zoology, 267(3), 1993, pp. 337-343
The two cell populations of the day 5 mouse blastocyst-the inner cell
mass (ICM) and trophectoderm (TE)-were isolated by immunosurgery and T
E biopsy. The uptake of glucose and pyruvate and the production of lac
tate were measured in the isolated cell populations and in single day
5 blastocysts, using a non-invasive ultramicrofluorescence technique.
The number of cells in isolated ICMs, TE vesicles, and intact blastocy
sts were counted after differential labeling with fluorochromes. The u
ptake of glucose and the formation of lactate were approximately three
and five times greater, respectively, in the ICM cells compared with
the TE cells. All the glucose consumed by the ICM could be accounted f
or by lactate formation, whereas the value for TE was 55%. The uptake
of pyruvate was low in both cell types. The results are consistent wit
h the proposition that the TE acts as a transporting epithelium, spari
ng nutrients for metabolism by the ICM. (C) 1993 Wiley-Liss, Inc.