Metabolism of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine in the human neutrophil

Journal Article · Mon Apr 15 04:00:00 EDT 1991 · Journal of Biological Chemistry; (USA)

OSTI ID:5802826

Triggiani, M; D'Souza, D M; Chilton, F H ^[1]

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1. Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA)

The biosynthesis of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (1-acyl-2-acetyl-GPC) together with that of 1-alkyl-2-acetyl-GPC (platelet-activating factor) has been demonstrated in a variety of inflammatory cells and tissues. It has been hypothesized that the relative proportion of these phospholipids produced upon cell activation may be influenced by their rates of catabolism. We studied the catabolism of 1-acyl-2-acetyl-GPC in resting and activated human neutrophils and compared it to that of 1-alkyl-2-acetyl-GPC. Neutrophils rapidly catabolize both 1-alkyl-2-acetyl-GPC and 1-acyl-2-acetyl-GPC; however, the rate of catabolism of 1-acyl-2-acetyl-GPC is approximately 2-fold higher than that of 1-alkyl-2-acetyl-GPC. In addition, most of 1-acyl-2-acetyl-GPC is catabolized through a pathway different from that of 1-alkyl-2-acetyl-GPC. The main step in the catabolism of 1-acyl-2-acetyl-GPC is the removal of the long chain at the sn-1 position; the long chain residue is subsequently incorporated either into triglycerides or into phosphatidylcholine. The 1-lyso-2-acetyl-GPC formed in this reaction is then further degraded to glycerophosphocholine, choline, or phosphocholine. 1-Acyl-2-acetyl-GPC is also catabolized, to a lesser extent, through deacetylation at the sn-2 position and reacylation with a long chain fatty acid. Stimulation of neutrophils by A23187 results in a higher rate of catabolism of 1-acyl-2-acetyl-GPC by increasing both the removal of the long chain at the sn-1 position and the deacetylation-reacylation at the sn-2 position. In a broken cell preparation, the cytosolic fraction of the neutrophil was shown to contain an enzyme activity which cleaved the sn-1 position of 1-acyl-2-acetyl-GPC and 1-acyl-2-lyso-GPC but not of 1,2-diacyl-GPC.

• OSTI ID: 5802826
• Journal Information: Journal of Biological Chemistry; (USA), Journal Name: Journal of Biological Chemistry; (USA) Vol. 266:11; ISSN JBCHA; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACYLATION
ANIMALS
BIOLOGICAL FUNCTIONS
BIOLOGICAL MATERIALS
BIOLOGICAL PATHWAYS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBON ISOTOPES
CATABOLISM
CHEMICAL REACTIONS
ENZYME ACTIVITY
ESTERS
FUNCTIONS
HYDROGEN COMPOUNDS
IN VITRO
ISOTOPE APPLICATIONS
ISOTOPE DILUTION
ISOTOPES
LEUKOCYTES
LIPIDS
MAMMALS
MAN
MATERIALS
METABOLISM
NEUTROPHILS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
PRIMATES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES