Phosphatidylcholine formation from exogenous lysophosphatidylcholine in isolated hamster heart.

The formation of phosphatidylcholine in hamster heart by reacylation and transacylation of exogenous lysophosphatidylcholine was investigated. Isolated hamster hearts were perfused with labeled lysophosphatidylcholine in Krebs-Henseleit buffer. Uptake of total radioactivity by the heart was maximum at 30 min of perfusion and was also linear from 5-20 mu M of lysophosphatidylcholine in the perfusate. About 17 +/- 3% of total radioactivity taken up by the heart was recovered in phosphatidylcholine. Perfusion of the isolated heart with 1-[14C]palmitoylglycerophospho[methyl-3H]choline indicated that labeled phosphatidylcholine was formed by reacylation of lysophosphatidylcholine with acyl-CoA and not by transacylation with another molecule of lysophosphatidylcholine. From the pool size of total cardiac lysophosphatidylcholine, the amount of phosphatidylcholine formed via the reacylation process was estimated to be 6.6 nmol/min per g heart.