M. Wojcik et al., Effect of ethanol on ATP-induced phospholipases C and D and serine base exchange in glioma C6 cells, NEUROCHEM I, 36(2), 2000, pp. 127-136
The effect of extracellular ATP, a nucleotide receptor agonist in the centr
al nervous system, was investigated in glioma C6 cells on the intracellular
Ca2+ level and the formation of phosphatidylethanol and phosphatidic acid
in the presence and absence of ethanol (150 mM). In the cells prelabeled wi
th [C-14]palmitic acid, 100 mu M ATP induced both the hydrolysis and the tr
ansphosphatidylation reactions leading to the formation of [C-14]phosphatid
ic acid; addition of ethanol generated [C-14]phosphatidylethanol. However,
ATP-mediated increase in the level of [C-14]phosphatidic acid was not inhib
ited by ethanol. Furthermore, ethanol augmented ATP-induced transient and s
ustained increase in the intracellular Ca2+ concentration, whereas ethanol
alone did not produce any change in the intracellular Ca2+ level. These res
ults indicate that in glioma C6 cells, ATP induces activation of polyphosph
oinositide-specific phospholipase C and phospholipase D and that ethanol en
hances this effect. In the present investigation we have also shown that lo
ng-term (2 days) ethanol treatment, at concentration relevant to chronic al
coholism (100 mM), decreased the incorporation of [C-14]serine into phospha
tidylserine. Since the effect of ethanol on ATP-induced activities of phosp
holipase C and phospholipase D and on serine base-exchange in glioma C6 cel
ls differs significantly from that in cultured neuronal cells, these result
s may contribute to a better understanding of the mechanisms of ethanol act
ion in cells of glial origin. (C) 2000 Elsevier Science Ltd. All rights res
erved.