期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1974
卷号：71
期号：4
页码：1056-1060
DOI：10.1073/pnas.71.4.1056
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The reason for the failure of early-stage mouse embryos to grow on glucose alone was investigated by measurement of glucose-6-phosphate, fructose-1,6-bisphosphate plus triose phosphates, citrate, and malate in individual embryos during starvation and refeeding with glucose or glucose plus pyruvate. The results indicate a block at the 6-phosphofructokinase (EC 2.7.1.11 ) step at early stages, which is later removed. Although there seems to be no early difficulty in phosphorylation of glucose, maximum glucose-6-phosphate levels (and probably fructose-6-phosphate levels) are much lower at early stages than at later stages. The increase in fructose-6-phosphate with age may be the major cause of the increase in 6-phosphofructokinase activity. Unusually high citrate levels at all ages may help to keep this enzyme strongly inhibited until the increase in fructose-6-phosphate occurs. The changes in metabolite levels also indicate an early defect in mobilization of glycogen and a probably less important defect in the citrate cycle.
