Inhibitory effects of GMCHA-OPhBut on phospholipid methylation and histamine release in mast cells activated by concanavalin A, anti-IgE, and antigen

J Biochem. 1989 Feb;105(2):219-25. doi: 10.1093/oxfordjournals.jbchem.a122642.

Abstract

[3H]Methyl group incorporation and histamine secretion in rat mast cells induced by anti-IgE and con A were strongly inhibited by trans-4-guanidinomethylcyclohexanecarboxylic acid 4-tert-butylphenyl ester (GMCHA-OPhBut), a strong and specific inhibitor for pH 7 tryptase (Muramatsu et al. (1988) Biol. Chem. Hoppe-Seyler 369, 617-625) which is present in rat mast cells. The IC50s for these events were of the order of 10(-6) M. Addition of GMCHA-OPhBut after the maximal increase in [3H]methyl group incorporation in rat mast cells activated by con A and anti-IgE induced rapid reduction of the methylated phospholipid, and the later histamine release was strongly suppressed. Mast cells were prepared with Mg2+-free Tyrode-HEPES solution, and challenged with anti-IgE with or without Mg2+. With Mg2+, [3H]methyl group incorporation was enhanced, and histamine was secreted time-dependently. Without Mg2+, [3H]methyl group incorporation fell to one-third, whereas histamine secretion was not affected. These results were incompatible with the above results. From these results it was strongly suggested that a trypsin-like protease, probably pH 7 tryptase, is involved not only in the early events, such as activation of phosphatidylethanolamine methyltransferase I and/or II, but also in the late events such as histamine release, and phospholipid methylation is not associated with histamine secretion.

MeSH terms

  • Animals
  • Antibodies, Anti-Idiotypic / immunology
  • Antigens / immunology
  • Concanavalin A / pharmacology
  • Cyclohexanecarboxylic Acids / pharmacology*
  • Histamine Release / drug effects*
  • Immunoglobulin E / immunology
  • Male
  • Mast Cells / drug effects
  • Mast Cells / metabolism*
  • Methylation
  • Methyltransferases / metabolism
  • Pertussis Vaccine / immunology
  • Phosphatidyl-N-Methylethanolamine N-Methyltransferase
  • Phosphatidylethanolamine N-Methyltransferase
  • Phospholipids / metabolism*
  • Rats
  • Rats, Inbred Strains

Substances

  • Antibodies, Anti-Idiotypic
  • Antigens
  • Cyclohexanecarboxylic Acids
  • Pertussis Vaccine
  • Phospholipids
  • anti-IgE antibodies
  • Concanavalin A
  • Immunoglobulin E
  • NCO 650
  • Methyltransferases
  • Phosphatidylethanolamine N-Methyltransferase
  • Phosphatidyl-N-Methylethanolamine N-Methyltransferase