title: The turnover of cyclic AMP in cultured fibroblasts.
abstract: The determination of the turnover of cAMP in WI-38 and VA13 cultured fibroblasts stimulated by prostaglandin E1 is reported. The method made use of data obtained from a process of continuously labeling the cellular adenine nucleotide pools by incubation with [3H]-adenine. The turnover of the cAMP was estimated from the delay in appearance of tritium label in the cAMP pool was compared to the cellular ATP. For WI-38 cells the half-life of cAMP when accumulation had reached a steady-state was 1.46 minutes; in the presence of 0.5 mM 1-methyl-3-isobutylxanthine (IBMX) the half-life was increased to 9.24 minutes. For VA13 transformed fibroblasts the half-life of cAMP determined by this method was 6.30 minutes. cAMP in these latter cells in the absence of hormone had a half-life of 3.01 minutes. This decrease supports the contention that the hormone has profound effects on phosphodiesterase as well as adenylate cyclase activities in these cells.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000196:embryology; D011458:Prostaglandins E / Q000494:pharmacology*
chemical_list: D011458:Prostaglandins E; D000242:Cyclic AMP; D015056:1-Methyl-3-isobutylxanthine