Inhibitory Effects of GMCHA-OPhBut on Phospholipid Methylation and Histamine Release in Mast Cells Activated by Concanavalin A, Anti-IgE, and Antigen

• Published in: Journal of biochemistry (Tokyo) 1989-02, Vol.105 (2), p.219-225
• Main Authors: Takei, Masao, Matumoto, Takahiro, Endo, Koichl, Muramatu, Mutumi
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Anti-Idiotypic - immunology; Antigens - immunology; Biological and medical sciences; Concanavalin A - pharmacology; Cyclohexanecarboxylic Acids - pharmacology; Fundamental and applied biological sciences. Psychology; Histamine Release - drug effects; Immunoglobulin E - immunology; Inflammation; Male; Mast Cells - drug effects; Mast Cells - metabolism; Methylation; Methyltransferases - metabolism; Molecular and cellular biology; Pertussis Vaccine - immunology; Phosphatidyl-N-Methylethanolamine N-Methyltransferase; Phosphatidylethanolamine N-Methyltransferase; Phospholipids - metabolism; Rats; Rats, Inbred Strains
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a122642

[3H]Methyl group incorporation and histamine secretion in rat mast cells induced by anti-IgE and con A were strongly inhibited by trans-4-guanidinomethylcyclohex-anecarboxylic acid 4-tert-butylphenyl ester (GMCHA-OPhBu1), 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.