Dibutyryl cyclic AMP effects on calcium metabolism by mouse mastocytoma cells.
The ability of mouse mastocytoma cells to take up 45Ca2+ was measured in normal growth medium. As previously observed in physiological buffers with succinate and Pi, cells grown for 18h with N6,O2'-dibutyryladenosine 3',5' cyclic monophosphate (DB cyclic AMP) to inhibit growth took up more 45Ca2+ than untreated cells. However 45Ca2+ uptake by cells in growth medium was less sensitive to respiratory inhibitors or uncouplers than 45Ca2+ uptake in physiological buffer. Increased 45Ca2+ uptake by 18h cyclic nucleotide-treated cells was not a result of tighter mitochondrial coupling since mitochondria prepared from cyclic nucleotide-treated cells were less coupled than those from untreated cells. Nevertheless studies with uncouplers suggested that the bulk of the intracellular Ca2+ was associated with mitochondria. DB cyclic AMP-treated cells contained less total Ca2+ than untreated cells indicating that net Ca2+ efflux occurred during the 18h period of drug treatment. These observations suggest that Ca2+ fluxes increase in DB cyclic AMP-treated PY815 cells and that a net efflux of Ca2+ occurs during growth inhibition by the cyclic nucleotide.
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002460:Cell Line; D003470:Culture Media; D004533:Egtazic Acid / Q000494:pharmacology; D012515:Mast-Cell Sarcoma / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D010710:Phosphates / Q000494:pharmacology; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D013806:Theophylline / Q000494:pharmacology
D002132:Calcium Radioisotopes; D003470:Culture Media; D010710:Phosphates; D013386:Succinates; D004533:Egtazic Acid; D003994:Bucladesine; D019802:Succinic Acid; D013806:Theophylline; D002118:Calcium