Skip to main content
PMC home page
Biochemical Journal logoLink to Biochemical Journal
. 1985 Aug 1;229(3):811–816. doi: 10.1042/bj2290811

Human platelets stimulated by thrombin produce platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) when the degrading enzyme acetyl hydrolase is blocked.

L Touqui, M Hatmi, B B Vargaftig
PMCID: PMC1145129  PMID: 4052028

Abstract

It has been shown [Touqui, Jacquemin & Vargaftig (1983) Thromb. Haemostasis 50, 163; Touqui, Jacquemin & Vargaftig (1983) Biochem. Biophys. Res. Commun. 110, 890-893; Alam, Smith & Melvin (1983) Lipids 18, 534-538; Pieroni & Hanahan (1983) Arch. Biochem. Biophys. 224, 485-493] that rabbit platelets inactivate exogenous PAF (platelet-activating factor, PAF-acether) by a deacetylation-reacylation mechanism. The deacetylation step is catalysed by an acetyl hydrolase sensitive to the serine-hydrolase inhibitor PMSF (phenylmethanesulphonyl fluoride) [Touqui, Jacquemin, Dumarey & Vargaftig (1985) Biochim. Biophys. Acta 833, 111-118]. We report here that human platelets can produce PAF on thrombin stimulation. This production is marginal and transient, reaching a maximum at 10 min and decreasing thereafter. In contrast, 10-12 times more PAF is produced when platelets are treated with PMSF and stimulated with thrombin. Under these conditions, the maximum formation is observed at 30 min and no decline occurs for up to 60 min after stimulation. In addition, these platelets (treated with PMSF and stimulated with thrombin) incorporate exogenous labelled acetate in the 2-position of PAF, probably by an acetyltransferase-dependent mechanism. Production of PAF by human platelets during physiological stimulation can be demonstrated when PAF degradation is suppressed by the acetyl-hydrolase inhibitor PMSF.

Full text

PDF
811

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alam I., Smith J. B., Silver M. J. Metabolism of platelet-activating factor by blood platelets and plasma. Lipids. 1983 Aug;18(8):534–538. doi: 10.1007/BF02535393. [DOI] [PubMed] [Google Scholar]
  2. Albert D. H., Snyder F. Biosynthesis of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet-activating factor) from 1-alkyl-2-acyl-sn-glycero-3-phosphocholine by rat alveolar macrophages. Phospholipase A2 and acetyltransferase activities during phagocytosis and ionophore stimulation. J Biol Chem. 1983 Jan 10;258(1):97–102. [PubMed] [Google Scholar]
  3. Alonso F., Gil M. G., Sánchez-Crespo M., Mato J. M. Activation of 1-alkyl-2-lysoglycero-3-phosphocholine. Acetyl-CoA transferase during phagocytosis in human polymorphonuclear leukocytes. J Biol Chem. 1982 Apr 10;257(7):3376–3378. [PubMed] [Google Scholar]
  4. BLIGH E. G., DYER W. J. A rapid method of total lipid extraction and purification. Can J Biochem Physiol. 1959 Aug;37(8):911–917. doi: 10.1139/o59-099. [DOI] [PubMed] [Google Scholar]
  5. Barber A. J., Jamieson G. A. Isolation and characterization of plasma membranes from human blood platelets. J Biol Chem. 1970 Dec 10;245(23):6357–6365. [PubMed] [Google Scholar]
  6. Benveniste J., Chignard M., Le Couedic J. P., Vargaftig B. B. Biosynthesis of platelet-activating factor (PAF-ACETHER). II. Involvement of phospholipase A2 in the formation of PAF-ACETHER and lyso-PAF-ACETHER from rabbit platelets. Thromb Res. 1982 Mar 1;25(5):375–385. doi: 10.1016/0049-3848(82)90128-1. [DOI] [PubMed] [Google Scholar]
  7. Benveniste J., Le Couedic J. P., Polonsky J., Tence M. Structural analysis of purified platelet-activating factor by lipases. Nature. 1977 Sep 8;269(5624):170–171. doi: 10.1038/269170a0. [DOI] [PubMed] [Google Scholar]
  8. Benveniste J., Tencé M., Varenne P., Bidault J., Boullet C., Polonsky J. Semi-synthèse et structure proposée du facteur activant les plaquettes (P.A.F.): PAF-acether, un alkyl ether analogue de la lysophosphatidylcholine. C R Seances Acad Sci D. 1979 Nov 26;289(14):1037–1040. [PubMed] [Google Scholar]
  9. Blank M. L., Cress E. A., Whittle T., Snyder F. In vivo metabolism of a new class of biologically active phospholipids: 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine, a platelet activating-hypotensive phospholipid. Life Sci. 1981 Aug 24;29(8):769–775. doi: 10.1016/0024-3205(81)90031-x. [DOI] [PubMed] [Google Scholar]
  10. Blank M. L., Lee T., Fitzgerald V., Snyder F. A specific acetylhydrolase for 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (a hypotensive and platelet-activating lipid). J Biol Chem. 1981 Jan 10;256(1):175–178. [PubMed] [Google Scholar]
  11. Cazenave J. P., Benveniste J., Mustard J. F. Aggregation of rabbit platelets by platelet-activating factor is independent of the release reaction and the arachidonate pathway and inhibited by membrane-active drugs. Lab Invest. 1979 Sep;41(3):275–285. [PubMed] [Google Scholar]
  12. Chap H., Mauco G., Simon M. F., Benveniste J., Douste-Blazy L. Biosynthetic labelling of platelet activating factor from radioactive acetate by stimulated platelets. Nature. 1981 Jan 22;289(5795):312–314. doi: 10.1038/289312a0. [DOI] [PubMed] [Google Scholar]
  13. Chignard M., Le Couedic J. P., Tence M., Vargaftig B. B., Benveniste J. The role of platelet-activating factor in platelet aggregation. Nature. 1979 Jun 28;279(5716):799–800. doi: 10.1038/279799a0. [DOI] [PubMed] [Google Scholar]
  14. Chignard M., Le Couedic J. P., Vargaftig B. B., Benveniste J. Platelet-activating factor (PAF-acether) secretion from platelets: effect of aggregating agents. Br J Haematol. 1980 Nov;46(3):455–464. doi: 10.1111/j.1365-2141.1980.tb05993.x. [DOI] [PubMed] [Google Scholar]
  15. Demopoulos C. A., Pinckard R. N., Hanahan D. J. Platelet-activating factor. Evidence for 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine as the active component (a new class of lipid chemical mediators). J Biol Chem. 1979 Oct 10;254(19):9355–9358. [PubMed] [Google Scholar]
  16. Hendon R. A., Fraenkel-Conrat H. Biological roles of the two components of crotoxin. Proc Natl Acad Sci U S A. 1971 Jul;68(7):1560–1563. doi: 10.1073/pnas.68.7.1560. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Hwang S. B., Lee C. S., Cheah M. J., Shen T. Y. Specific receptor sites for 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphocholine (platelet activating factor) on rabbit platelet and guinea pig smooth muscle membranes. Biochemistry. 1983 Sep 27;22(20):4756–4763. doi: 10.1021/bi00289a022. [DOI] [PubMed] [Google Scholar]
  18. Iñarrea P., Gomez-Cambronero J., Nieto M., Crespo M. S. Characteristics of the binding of platelet-activating factor to platelets of different animal species. Eur J Pharmacol. 1984 Oct 15;105(3-4):309–315. doi: 10.1016/0014-2999(84)90623-x. [DOI] [PubMed] [Google Scholar]
  19. Kramer R. M., Patton G. M., Pritzker C. R., Deykin D. Metabolism of platelet-activating factor in human platelets. Transacylase-mediated synthesis of 1-O-alkyl-2-arachidonoyl-sn-glycero-3-phosphocholine. J Biol Chem. 1984 Nov 10;259(21):13316–13320. [PubMed] [Google Scholar]
  20. Mustard J. F., Perry D. W., Ardlie N. G., Packham M. A. Preparation of suspensions of washed platelets from humans. Br J Haematol. 1972 Feb;22(2):193–204. doi: 10.1111/j.1365-2141.1972.tb08800.x. [DOI] [PubMed] [Google Scholar]
  21. Ninio E., Mencia-Huerta J. M., Heymans F., Benveniste J. Biosynthesis of platelet-activating factor. I. Evidence for an acetyl-transferase activity in murine macrophages. Biochim Biophys Acta. 1982 Jan 15;710(1):23–31. doi: 10.1016/0005-2760(82)90185-0. [DOI] [PubMed] [Google Scholar]
  22. Pieroni G., Hanahan D. J. Metabolic behavior of acetyl glyceryl ether phosphorylcholine on interaction with rabbit platelets. Arch Biochem Biophys. 1983 Jul 15;224(2):485–493. doi: 10.1016/0003-9861(83)90236-9. [DOI] [PubMed] [Google Scholar]
  23. Touqui L., Jacquemin C., Dumarey C., Vargaftig B. B. 1-O-alkyl-2-acyl-sn-glycero-3-phosphorylcholine is the precursor of platelet-activating factor in stimulated rabbit platelets. Evidence for an alkylacetyl-glycerophosphorylcholine cycle. Biochim Biophys Acta. 1985 Jan 9;833(1):111–118. doi: 10.1016/0005-2760(85)90258-9. [DOI] [PubMed] [Google Scholar]
  24. Touqui L., Jacquemin C., Vargaftig B. B. Conversion of 3H-PAF acether by rabbit platelets is independent from aggregation: evidences for a novel metabolite. Biochem Biophys Res Commun. 1983 Feb 10;110(3):890–893. doi: 10.1016/0006-291x(83)91045-8. [DOI] [PubMed] [Google Scholar]
  25. Vargaftig B. B., Chignard M., Benveniste J., Lefort J., Wal F. Background and present status of research on platelet-activating factor (PAF-acether). Ann N Y Acad Sci. 1981;370:119–137. doi: 10.1111/j.1749-6632.1981.tb29727.x. [DOI] [PubMed] [Google Scholar]
  26. Wykle R. L., Malone B., Snyder F. Enzymatic synthesis of 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine, a hypotensive and platelet-aggregating lipid. J Biol Chem. 1980 Nov 10;255(21):10256–10260. [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES