The Composition of Phospholipid and Phospholipase-A Activity in the Rat Submaxillary Gland (Part 1)

1. A detailed composition of phospholipid has been examined in the rat submaxillary gland. It was recognized that there is phosphatidylcholine, phosphatidyl-ethanolamine (possibly containing phosphatidylserine) and sphingomyeline as a major constituent of phospholipids, that there is trace of lysophosphatidylcholine and unknown phospholipid. 2. The phospholipase A activity of unpurified tissue extract (fraction A) or purified tissue extract (fraction D), as the source of enzyme has been examined. The fraction A or fraction D hydrolysed phosphatidylcholine as a substrate, and liberate free fatty acid and formed lysophosphatidylcholine. From above results, it was established that phospholipase A activity is present in the rat submaxillary gland.