Regulatory enzymes of carbohydrate and energy metabolism in the rabbit blastocyst.

The activities of phosphofructokinase, pyruvate kinase, citrate synthase and creatine kinase were determined in blastocysts from rabbits at 144 h post coitum and in similar blastocysts cultured for 24 h with or without oestradiol-17beta (1 microgrm/ml). There was a significant increase in all the enzymes during the 24-h culture period but oestradiol had no effect.