leukotriene-e4 and diazobenzenesulfonic-acid

Metabolism of sulfidopeptide leukotrienes, leukotrienes (LT) C4 and D4 by rat peritoneal mast cells was studied. Rat peritoneal mast cells converted LTD4 to LTE4 but not LTC4 to LTD4. The LTD4-metabolizing activity was equally distributed on the cell surface and inside cells, but not released to the extracellular milieu even when a considerable portion of histamine and the secretory granule enzymes were released. Among various enzyme inhibitors examined, o-phenanthroline, a metal chelator, and dithiothreitol significantly suppressed the LTD4-metabolizing activity of mast cell. These results would suggest that some metalloenzyme located on the cell surface is involved in the conversion of LTD4 to LTE4 by rat peritoneal mast cells.

Topics: Animals; beta-N-Acetylhexosaminidases; Chromatography, High Pressure Liquid; Chymases; Cysteine; Diazonium Compounds; Dipeptidases; Dithiothreitol; Histamine; Kinetics; L-Lactate Dehydrogenase; Leukotriene E4; Mast Cells; Peritoneum; Phenanthrolines; Rats; Rats, Inbred Strains; Serine Endopeptidases; SRS-A; Sulfanilic Acids