Dietary ethanol stimulates the activity of phosphatidylcholine-specific phospholipase D and the formation of phosphatidylethanol in Drosophila melanogaster larvae

Abstract When administered in the diet to third instar Drosophila melanogaster larvae, short chain primary alcohols reduce phosphatidylcholine (PC) levels. The ethanol-induced reductions in larval PC may be in part due to an increase in the activity of PC-specific phospholipase D (PC-specific PLD, EC 3.1.4.4). PC-specific PLD not only hydrolyzes PC, but it also apparently catalyzes the formation of phosphatidylethanol. PC-specific PLD activity was also stimulated by 200 mM ethanol, methanol, isopropanol, n -butanol, and n -propanol. In vitro studies indicated that Drosophila PC-specific PLD activities were enhanced by submicromolar concentrations of Ca 2+ and by GTP-γS. In vivo studies utilizing [ 14 C]lyso-palmitoyl phosphatidylcholine indicated that dietary ethanol promoted the flux of label into triacylgycerol, 1,2 diacylgycerol, and fatty acid ethyl esters, while the label in PC decreased.