New patterns of diacylglycerol metabolism in intact cells.

The metabolism of di[1-14C]octanoylglycerol metabolism was examined in four cell lines: NIH 3T3 fibroblasts, BHK cells, Pam 212 keratinocytes and WEHI 3BD+ cells. We found the direct conversion of 1,2-di[1-14C]octanoyl-sn-glycerol ([14C]diC8) into dioctanoylphosphatidylcholine and dioctanoylacylglycerol, but no formation of phosphatidylinositol. The [14C]diC8 also underwent lipolytic breakdown. In contrast, 1-[1-14C]oleoyl-2-acetyl-sn-glycerol was metabolized exclusively by lipolysis. Our findings support a new scheme for the metabolic termination of diacylglycerol signals.