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：1973
卷号：70
期号：12
页码：3609-3612
DOI：10.1073/pnas.70.12.3609
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Serum or insulin added to quiescent mouse-embryo fibroblasts produced rapid increases in the rate of transport of uridine and phosphate and a decrease of the intracellular concentration of cyclic AMP. Incubation of the cells with prostaglandin E1, theophylline, or both prevented the increase in uridine transport produced by serum or insulin. Prostaglandin E1 was more effective than prostaglandins E2 and B1. Kinetic experiments showed that the addition of prostaglandin E1 and theophylline causes the uridine transport rate to return to the basal level within 5 min; the rate rose rapidly after their removal. Similar effects were obtained when insulin was used instead of serum. Associated with these transport changes were significant variations in the levels of cyclic AMP. An inverse correlation between the changes in uridine transport and those in cyclic AMP concentration was shown under various experimental conditions. In contrast to the effects observed with uridine transport, phosphate uptake was only slightly affected by changes in the endogenous level of cyclic AMP. We propose that at least two different sorts of membrane changes are rapidly initiated by serum, one under cyclic AMP control and the other not related to this nucleotide.
