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：1972
卷号：69
期号：1
页码：269-273
DOI：10.1073/pnas.69.1.269
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Incubation of L-929 and L-2071 fibroblasts with prostaglandin E1 (PGE1) caused a rapid increase in the cyclic AMP content of these cells. A maximal effect was produced with 0.2 {micro}g PGE1 per ml. At a concentration of 4 {micro}g/ml, PGE2 was almost equally effective, but PGF2[α] and PGA2 were much less so. 2.6 {micro}M epinephrine, 0.4 mM serotonin, and 0.2% ethanol were without effect. In L-929 cells, cyclic AMP concentrations remained elevated for 2-5 hr, and then declined, although even after a 24-hr incubation the medium contained PGE1 in a concentration sufficient to increase maximally the cyclic AMP content of cells not previously exposed to this compound. A second addition of PGE1 after 5 or 24 hr did not produce another increase in the concentration of cyclic AMP. After incubation with PGE1 for 24 hr, cyclic AMP phosphodiesterase activity, assayed with 0.56 {micro}M substrate, was increased 30-100%; the activity rose further between 24 and 48 hr. It is suggested that the increase in phosphodiesterase activity that appears to be a consequence of prolonged elevation of cyclic AMP concentration may account at least in part for the apparent "refractoriness" to PGE1 that develops after incubation for several hours with this compound.
