J. Biol. Chem., Vol. 261, Issue 23, 10713-10718, 08, 1986
Leukotriene D4 treatment of bovine aortic endothelial cells and murine smooth muscle cells in culture results in an increase in phospholipase A2 activity
MA Clark, D Littlejohn, TM Conway, S Mong, S Steiner and ST Crooke
Leukotriene D4 stimulates prostanoid synthesis in smooth muscle and
endothelial cells. Because phospholipases A2 and C have been proposed to
regulate prostanoid synthesis, we examined the effect of leukotriene D4 on
these activities. Leukotriene D4 treatment resulted in a dose- dependent,
stereospecific increase in phospholipase A2 activity with
phosphatidylcholine as a substrate. The induction of phospholipase A2
activity occurred just prior to the appearance of prostanoids in the media.
Protein and RNA synthesis were required for the increase in phospholipase
A2 activity, and the increase in activity resulted from an increase in the
apparent Vmax of the phospholipase A2 enzyme. Phospholipase C activity
using various substrates was unchanged. We conclude that the increase in
prostanoid synthesis observed after leukotriene D4 treatment is a result of
an increase in a phospholipase A2 activity.