title: Exit transport of a cyclic nucleotide from mouse L-cells.
abstract: At a concentration of 30 mum, 1,4,5,6,8-pentazaacenaphthylene, 3-amino-1,5-dihydro-5-methyl-1-beta-D-[5-14C]ribofuranosyl (NSC-154020), a tricyclic, 7-deazapurine nucleoside (TCN) is rapidly taken up by cultured mouse L-cells and converted to intracellular TCN-monophosphate, but not further metabolized. The TCN-monophosphate is also excreted by the cells into the medium. It is released by a saturable process against a concentration gradient and the release is inhibited by various inhibitors of energy production. This inhibition correlates with a depletion of the cells of ATP. Thus TCN-monophosphate excretion probably involves an active transport system. This transport system is highly temperature-dependent (the Q10 falls between 3 and 4) and is inhibited by papaverine, theophylline, Persantin, Probenecid, phenethyl alcohol and p-chloromercuribenzoate, but not by 500 muM cyclic AMP, AMP, or adenosine. Significant amounts of various natural phosphorylated intermediates (AMP, ATP, UTP, UMP, UDP-hexoses, and phosphorylcholine) are not released from the cells under similar experimental conditions either in the absence or presence of 30 muM TCN.
mesh_terms: D000073:Acenaphthenes; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport; D003486:Cyanides / Q000494:pharmacology; D004140:Dinitrophenols / Q000494:pharmacology; D007461:Iodoacetates / Q000494:pharmacology; D007700:Kinetics; D007739:L Cells / Q000187:drug effects / Q000378:metabolism*; D012263:Ribonucleosides / Q000378:metabolism*; D012265:Ribonucleotides / Q000378:metabolism*; D013696:Temperature
chemical_list: D000073:Acenaphthenes; D001386:Azides; D003486:Cyanides; D004140:Dinitrophenols; D007461:Iodoacetates; D012263:Ribonucleosides; D012265:Ribonucleotides; C023764:triciribine; C014205:triciribine phosphate