A novel and sensitive assay for phospholipase D in intact cells.

A novel and sensitive assay for phospholipase D (PLD) that measures the incorporation of high specific activity [3H]butan-1-ol into [3H]phosphatidylbutanol has been developed. The assay has been used to measure PLD activation in human neutrophils and platelets. Both the chemotactic peptide fMet-Leu-Phe and opsonised-zymosan stimulated PLD in the human neutrophil. In the platelet, PLD was stimulated by thrombin and collagen but responses were small and only occurred at high agonist concentrations. This assay has a number of advantages over existing techniques and should be valuable for investigating PLD activation in a variety of isolated cells and possibly intact tissues.