ABSTRACT
This chapter provides the most frequently used methods for assessment of Phospholipase D (PLD) activity. The activation of PLD has been demonstrated in a variety of cells stimulated by agonists, including hormones, peptides, cytokines, neurotransmitters, growth factors, and nonphysiological stimuli, such as phorbol esters and calcium ionophores. The earliest report of PLD was of a phosphatidase C in carrot roots and cabbage leaves employing phosphatidylcholine as the substrate. The rapid increase in recent publications about PLD was facilitated by the unusual property of PLD to catalyze a “transphosphatidylation” reaction. The measurement of PLD activity in intact cells is dependent upon an increase from a finite baseline of an expected product. The measurement of phosphatidic acid, phosphatidylethanol, or choline formation is employed as an index of PLD activity.
