Cleavage of phosphatidylcholine: an additional mechanism for stimulation of macrophage eicosanoid synthesis?
Cleavage of phosphatidylcholine (PtdChol) as putative mechanism leading to enhanced eicosanoid synthesis was investigated in mouse peritoneal macrophages. Addition of 12-O-tetradecanoylphorbol 13-acetate (TPA) to intact [3H]choline-labelled cells did not enhance radioactivity release above control levels. Membrane-bound PtdChol-specific phospholipase (PL) activity was then measured in a cell-free assay using [3H]choline-labelled membranes as endogenous substrate. Preincubation of macrophages with TPA increased PL activity in a time course resembling the one observed for protein kinase C (PKC) activation. Diacylglycerol (DAG) species derived from PtdChol might therefore serve as additional stimulator of rapid macrophage eicosanoid synthesis via PKC.
Kaever
V
V
Institut für Molekularpharmakologie, Medizinische Hochschule Hannover, FRG.
Sommermeyer
H
H
Resch
K
K
D000818:Animals; D002794:Choline / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism; D015777:Eicosanoids / Q000096:biosynthesis*; D004789:Enzyme Activation; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008811:Mice, Inbred DBA; D010529:Peritoneal Cavity / Q000166:cytology; D010713:Phosphatidylcholines / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
D004075:Diglycerides; D015777:Eicosanoids; D010713:Phosphatidylcholines; D011493:Protein Kinase C; D010738:Type C Phospholipases; D010739:Phospholipase D; D002794:Choline; D013755:Tetradecanoylphorbol Acetate