Biosynthesis of paf-acether. XIV. Paf-acether output in murine peritoneal macrophages is regulated by the level of acetylhydrolase.
Paf-acether (paf) synthesis was previously shown to be impaired in 24 hr-adherent and Bacillus Calmette-Guérin-activated murine peritoneal macrophages as compared to resident macrophages. We report here that the induction of acetylhydrolase was responsible for the decreased paf output in 24 hr-adherent macrophages. The kinetic analysis of the enzymes derived from 2 hr-, 24 hr- and BCG-activated adherent macrophages and from plasma revealed that the Km for paf was similar whatever the source of the acetylhydrolase whereas the Vmax was five-fold increased in 24 hr-cultured macrophages. The acetylhydrolase activity was Ca2+-independent and was not inhibited by addition of alkyl-acyl (long chain)-glycero-phosphocholine suggesting that the enzyme was not a phospholipase A2.
Palmantier
R
R
INSERM U.200, Université Paris-Sud, Clamart, France.
Dulioust
A
A
Maiza
H
H
Benveniste
J
J
Ninio
E
E
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000818:Animals; D002458:Cell Fractionation; D002478:Cells, Cultured; D008262:Macrophage Activation; D008264:Macrophages / Q000201:enzymology* / Q000378:metabolism; D051379:Mice; D010529:Peritoneal Cavity; D010740:Phospholipases / Q000502:physiology*; D010741:Phospholipases A / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D054467:Phospholipases A2; D010972:Platelet Activating Factor / Q000096:biosynthesis* / Q000378:metabolism
D010972:Platelet Activating Factor; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase