Production of carbon dioxide in vitro by blastocysts from intact and ovariectomized mice.
'Normal' and 'delayed implanting' mouse blastocysts were incubated in non-radioactive culture medium for various lengths of time (preincubation), and then placed in culture medium with (14-C)-glucose for 2 hr. The rate of embryonic CO-2 given off by the blastocysts. Normal embryos were unaffected by the length of preincubation. By contrast, 'delayed implantating' embryos had a low level of CO-2 production with short preincubations (i.e. less than 2 hr), but approached  the normal range with longer preincubations (i.e. more than 8 hr) and thus, were 'activated ' in vitro. Incubation of the 'delayed implanting' embryos with actinomycin D prevented the expected increase in CO-2 production, indicating that synthesis of new RNA  is necessary for their activation. Preincubation of normal and 'delayed implanting' blastocysts with oestradiol-17 beta and/ or progesterone had no effect on the level of CO-2 production, suggesting that the hormones do not directly stimulate or inhibit carbohydrate metabolism in the embryos.
D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002245:Carbon Dioxide / Q000096:biosynthesis*; D002250:Carbon Radioisotopes; D002369:Castration; D003470:Culture Media; D003609:Dactinomycin / Q000494:pharmacology; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D051379:Mice; D010053:Ovary / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology; D012313:RNA / Q000096:biosynthesis; D013223:Statistics as Topic; D013997:Time Factors
D002250:Carbon Radioisotopes; D003470:Culture Media; D002245:Carbon Dioxide; D003609:Dactinomycin; D011374:Progesterone; D004958:Estradiol; D012313:RNA