McQuillan J, Wojcik S J, Ralph R K
Cell Calcium. 1984 Apr;5(2):131-42. doi: 10.1016/0143-4160(84)90012-5.
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.
在正常生长培养基中测定了小鼠肥大细胞瘤细胞摄取45Ca2+的能力。如先前在含有琥珀酸盐和无机磷酸盐的生理缓冲液中所观察到的，用N6,O2'-二丁酰腺苷3',5'-环一磷酸（DB环磷腺苷）培养18小时以抑制生长的细胞比未处理的细胞摄取更多的45Ca2+。然而，生长培养基中细胞对45Ca2+的摄取对呼吸抑制剂或解偶联剂的敏感性低于生理缓冲液中45Ca2+的摄取。经18小时环核苷酸处理的细胞对45Ca2+摄取的增加并非线粒体偶联更紧密的结果，因为从经环核苷酸处理的细胞中制备的线粒体比未处理细胞的线粒体偶联性更弱。尽管如此，用解偶联剂进行的研究表明，细胞内大部分Ca2+与线粒体相关。经DB环磷腺苷处理的细胞比未处理的细胞总Ca2+含量少，这表明在药物处理的18小时期间发生了净Ca2+外流。这些观察结果表明，经DB环磷腺苷处理的PY815细胞中Ca2+通量增加，并且在环核苷酸抑制生长期间发生了Ca2+的净外流。
