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. 1977 Apr;74(4):1716–1720. doi: 10.1073/pnas.74.4.1716

Application of imidazole as a selective inhibitor thromboxane synthetase in human platelets.

P Needleman, A Raz, J A Ferrendelli, M Minkes
PMCID: PMC430864  PMID: 193113

Abstract

Human platelet suspensions release a rabbit-aorta-contracting substance (previously identified as thromboxane A2) during aggregation produced by arachidonic acid, prostaglandin endoperoxide, thrombin, and collagen. Incubation of platelets with imidazole did not interfere with the aggregation produced by these agonists but markedly reduced the generation of the rabbit-aorta-contracting substance. We find that imidazole inhibited the conversion of exogenous or endogenous prostaglandin endoperoxide into thromboxane A2-Imidazole selectively inhibits thromboxane synthetase in intact human platelets, because this agent blocks the conversion of [14C]arachidonate into [14C]thromboxane B2 but does not inhibit the conversion of [14C]arachidonate into [14C]prostaglandin E2. The inhibition of thromboxane synthetase by imidazole is not the result of an alteration in platelet 3':5'-cyclic AMP levels. These results illustrate the utility of imidazole as a pharmacological tool and demonstrate the two unique and dissociable properties of the endoperoxides themselves--their ability to aggregate platelets and their enzymatic conversion to the potent vasoconstrictor thromboxane.

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Selected References

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

  1. BUTCHER R. W., SUTHERLAND E. W. Adenosine 3',5'-phosphate in biological materials. I. Purification and properties of cyclic 3',5'-nucleotide phosphodiesterase and use of this enzyme to characterize adenosine 3',5'-phosphate in human urine. J Biol Chem. 1962 Apr;237:1244–1250. [PubMed] [Google Scholar]
  2. Dawson W., Boot J. R., Cockerill A. F., Mallen D. N., Osborne D. J. Release of novel prostaglandins and thromboxanes after immunological challenge of guinea pig lung. Nature. 1976 Aug 19;262(5570):699–702. doi: 10.1038/262699a0. [DOI] [PubMed] [Google Scholar]
  3. Eakins K. E., Rajadhyaksha V., Schroer R. Prostaglandin antagonism by sodium p-benzyl-4-[1-oxo-2-(4-chlorobenzyl)-3-phenylpropyl]pheenyl phosphonate (N-0164). Br J Pharmacol. 1976 Nov;58(3):333–339. doi: 10.1111/j.1476-5381.1976.tb07709.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Eckenfels A., Vane J. R. Prostaglandins, oxygen tension and smooth muscle tone. Br J Pharmacol. 1972 Jul;45(3):451–462. doi: 10.1111/j.1476-5381.1972.tb08101.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Friedman W. F., Hirschklau M. J., Printz M. P., Pitlick P. T., Kirkpatrick S. E. Pharmacologic closure of patent ductus arteriosus in the premature infant. N Engl J Med. 1976 Sep 2;295(10):526–529. doi: 10.1056/NEJM197609022951003. [DOI] [PubMed] [Google Scholar]
  6. Gryglewski R., Vane J. R. The generation from arachidonic acid of rabbit aorta contracting substance (RCS) by a microsomal enzyme preparation which also generates prostaglandins. Br J Pharmacol. 1972 Nov;46(3):449–457. doi: 10.1111/j.1476-5381.1972.tb08142.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hamberg M., Samuelsson B. Detection and isolation of an endoperoxide intermediate in prostaglandin biosynthesis. Proc Natl Acad Sci U S A. 1973 Mar;70(3):899–903. doi: 10.1073/pnas.70.3.899. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hamberg M., Svensson J., Samuelsson B. Thromboxanes: a new group of biologically active compounds derived from prostaglandin endoperoxides. Proc Natl Acad Sci U S A. 1975 Aug;72(8):2994–2998. doi: 10.1073/pnas.72.8.2994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hamberg M., Svensson J., Wakabayashi T., Samuelsson B. Isolation and structure of two prostaglandin endoperoxides that cause platelet aggregation. Proc Natl Acad Sci U S A. 1974 Feb;71(2):345–349. doi: 10.1073/pnas.71.2.345. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Harper J. F., Brooker G. Femtomole sensitive radioimmunoassay for cyclic AMP and cyclic GMP after 2'0 acetylation by acetic anhydride in aqueous solution. J Cyclic Nucleotide Res. 1975;1(4):207–218. [PubMed] [Google Scholar]
  11. Heymann M. A., Rudolph A. M., Silverman N. H. Closure of the ductus arteriosus in premature infants by inhibition of prostaglandin synthesis. N Engl J Med. 1976 Sep 2;295(10):530–533. doi: 10.1056/NEJM197609022951004. [DOI] [PubMed] [Google Scholar]
  12. Isakson P. C., Raz A., Denny S. E., Pure E., Needleman P. A novel prostaglandin is the major product of arachidonic acid metabolism in rabbit heart. Proc Natl Acad Sci U S A. 1977 Jan;74(1):101–105. doi: 10.1073/pnas.74.1.101. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kulkarni P. S., Eakins K. E. N-0164 inhibits generation of thromboxane-A2-like activity from prostaglandin endoperoxides by human platelet microsomes. Prostaglandins. 1976 Sep;12(3):465–469. doi: 10.1016/0090-6980(76)90027-7. [DOI] [PubMed] [Google Scholar]
  14. Kulkarni P. S., Roberts R., Needleman P. Paradoxical endogenous synthesis of a coronary dilating substance from arachidonate. Prostaglandins. 1976 Sep;12(3):337–353. doi: 10.1016/0090-6980(76)90015-0. [DOI] [PubMed] [Google Scholar]
  15. Miller O. V., Gorman R. R. Modulation of platelet cyclic nucleotide content by PGE1 and the prostaglandin endoperoxide PGG2. J Cyclic Nucleotide Res. 1976;2(2):79–87. [PubMed] [Google Scholar]
  16. Moncada S., Gryglewski R., Bunting S., Vane J. R. An enzyme isolated from arteries transforms prostaglandin endoperoxides to an unstable substance that inhibits platelet aggregation. Nature. 1976 Oct 21;263(5579):663–665. doi: 10.1038/263663a0. [DOI] [PubMed] [Google Scholar]
  17. Moncada S., Needleman P., Bunting S., Vane J. R. Prostaglandin endoperoxide and thromboxane generating systems and their selective inhibition. Prostaglandins. 1976 Sep;12(3):323–335. doi: 10.1016/0090-6980(76)90014-9. [DOI] [PubMed] [Google Scholar]
  18. Needleman P., Kulkarni P. S., Raz A. Coronary tone modulation: formation and actions of prostaglandins, endoperoxides, and thromboxanes. Science. 1977 Jan 28;195(4276):409–412. doi: 10.1126/science.831285. [DOI] [PubMed] [Google Scholar]
  19. Needleman P., Minkes M., Raz A. Thromboxanes: selective biosynthesis and distinct biological properties. Science. 1976 Jul 9;193(4248):163–165. doi: 10.1126/science.945611. [DOI] [PubMed] [Google Scholar]
  20. Needleman P., Moncada S., Bunting S., Vane J. R., Hamberg M., Samuelsson B. Identification of an enzyme in platelet microsomes which generates thromboxane A2 from prostaglandin endoperoxides. Nature. 1976 Jun 17;261(5561):558–560. doi: 10.1038/261558a0. [DOI] [PubMed] [Google Scholar]
  21. Nugteren D. H., Hazelhof E. Isolation and properties of intermediates in prostaglandin biosynthesis. Biochim Biophys Acta. 1973 Dec 20;326(3):448–461. doi: 10.1016/0005-2760(73)90145-8. [DOI] [PubMed] [Google Scholar]
  22. Pace-Asciak C. Letter: Isolation, structure, and biosynthesis of 6-ketoprostaglandin F1 alpha in the rat stomach. J Am Chem Soc. 1976 Apr 14;98(8):2348–2349. doi: 10.1021/ja00424a065. [DOI] [PubMed] [Google Scholar]
  23. Pace-Asciak C., Wolfe L. S. A novel prostaglandin derivative formed from arachidonic acid by rat stomach homogenates. Biochemistry. 1971 Sep 28;10(20):3657–3664. doi: 10.1021/bi00796a004. [DOI] [PubMed] [Google Scholar]
  24. Piper P. J., Vane J. R. Release of additional factors in anaphylaxis and its antagonism by anti-inflammatory drugs. Nature. 1969 Jul 5;223(5201):29–35. doi: 10.1038/223029a0. [DOI] [PubMed] [Google Scholar]
  25. Steiner A. L., Parker C. W., Kipnis D. M. Radioimmunoassay for cyclic nucleotides. I. Preparation of antibodies and iodinated cyclic nucleotides. J Biol Chem. 1972 Feb 25;247(4):1106–1113. [PubMed] [Google Scholar]
  26. Wolfe L. S., Rostworowski K., Marion J. Endogenous formation of the prostaglandin endoperoxide metabolite, thromboxane B2, by brain tissue. Biochem Biophys Res Commun. 1976 Jun 7;70(3):907–913. doi: 10.1016/0006-291x(76)90677-x. [DOI] [PubMed] [Google Scholar]
  27. Wolfe S. M., Shulman N. R. Adenyl cyclase activity in human platelets. Biochem Biophys Res Commun. 1969 Apr 29;35(2):265–272. doi: 10.1016/0006-291x(69)90277-0. [DOI] [PubMed] [Google Scholar]

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