Nr. Aiken et al., METABOLISM OF PHOSPHONIUM CHOLINE BY RAT-2 FIBROBLASTS - EFFECTS OF MITOGENIC STIMULATION STUDIED USING P-31 NMR-SPECTROSCOPY, Anticancer research, 16(3B), 1996, pp. 1357-1363
Phospholipid turnover increases with both mitogenic stimulation and on
cogenic transformation (1-9). Recent P-31 nuclear magnetic resonance (
NMR) spectroscopy studies of human tumors, animal tumor models and cel
l systems have reported elevated phosphomonesters with growth and onco
genic transformation, as well as changes in these levels associated wi
th treatment (10). In order to gain insights into the mechanisms under
lying these changes, we used a phosphonium analog of choline and P-31
NMR spectroscopy to study choline metabolism in quiescent and mitogeni
cally stimulated Rat-2 fibroblasts. Cell growth status of these cells
has a significant effect on choline metabolism. While overall uptake o
f the analog was similar in both quiescent and growing cells, distribu
tion among metabolite pools differed. Quiescent cells accumulate label
in the phosphodiester pool, with little or none in the phosphomonoest
er pool. On the other hand, mitogenic stimulation resulted in a signif
icant fraction of the label in the phosphomonoester pool.