Phorbol myristate enhanced specific incorporation of arachidonic acid into phospholipids through lysophospholipid acyltransferase in cultured smooth muscle cells.

The effect of stimulation of phospholipase with phorbol 12-myristate 13-acetate and lipopolysaccharide on 1-acyl-glycerophospholipid acyltransferase was studied in cultured rabbit aorta smooth muscle cells. The acyltransferase in smooth muscle cells without stimulation was active on a wide range of unsaturated fatty acids and was not arachidonic acid specific. Upon increase in phospholipase activity, acyltransferase activity only with arachidonic acid as substrate increased in a time-dependent fashion. Apparent acyltransferase activity was increased most upon increase in phospholipase activity when lysophosphatidylcholine was used as acceptor. These results suggest that arachidonic acid specific acyltransferase was induced in smooth muscle cells by increase in phospholipase activity. The role of this acyltransferase is postulated to be the specific incorporation of endogenously released arachidonic acid.