Article thumbnail
Location of Repository

Role of Cyclic 3′:5′-Adenosine Monophosphate in the Early Transport Changes Induced by Serum and Insulin in Quiescent Fibroblasts

By Enrique Rozengurt and Luis Jimenez De Asua

Abstract

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 E(1), theophylline, or both prevented the increase in uridine transport produced by serum or insulin. Prostaglandin E(1) was more effective than prostaglandins E(2) and B(1). Kinetic experiments showed that the addition of prostaglandin E(1) 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

Topics: Biological Sciences: Biochemistry
Year: 1973
DOI identifier: 10.1073/pnas.70.12.3609
OAI identifier: oai:pubmedcentral.nih.gov:427290
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefore we are unable to provide a link to the full text.

Suggested articles


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.