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：1978
卷号：75
期号：9
页码：4189-4193
DOI：10.1073/pnas.75.9.4189
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Phosphoenolpyruvate carboxykinase (GTP) [GTP;oxaloacetate carboxy-lyase(transphosphorylating); EC 4.1.1.32 ] is absent in rat liver cytosol during fetal life and is synthesized initially at birth. De novo synthesis of the enzyme can be induced prematurely by injection of dibutyryl cyclic AMP or glucagon into fetal animals in utero. In this study a wheat germ translation assay was used to quantitate the level of total functional mRNA for phosphoenolpyruvate carboxykinase in the liver of fetal rats at 21 days of pregnancy under different induction situations. The translatable mRNA for the enzyme was marginally detectable in fetal rat liver. Administration of either glucagon or dibutyryl cyclic AMP to fetal rats in utero caused a marked induction of functional mRNA for this enzyme. Three hours after administration of dibutyryl cyclic AMP, the level of translatable mRNA increased almost 23-fold, but by 6 hr the level dropped approximately 60%. Administration of actinomycin D prior to dibutyryl cyclic AMP in 21-day fetal rats prevented the appearance of newly synthesized poly(A)-containing RNA in the cytoplasm as well as the induction of translatable mRNA for phosphoenolpyruvate carboxykinase. In animals delivered prematurely and maintained for varying periods, the translatable mRNA for the enzyme accumulated in the liver at a rate comparable to that observed for enzyme synthesis.
