Conversion of leukotriene C4 to leukotriene D4 by a cell-surface enzyme of rat macrophages.
Leukotriene (LT) C4-metabolizing enzyme was studied using rat leukocytes. Neutrophils and lymphocytes hardly metabolized LTC4, whereas macrophages rapidly converted LTC4 to LTD4. The LTC4-metabolizing enzyme of macrophages was present in the membrane fraction but not in the nuclear, granular and cytosol fractions. When macrophages were modified chemically with diazotized sulfanilic acid, a poorly permeant reagent which inactivates cell-surface enzymes selectively, the LTC4-metabolizing activity of macrophages decreased significantly (greater than 90%). These findings suggest that rat macrophages possess the LTC4-metabolizing enzyme which converts LTC4 to LTD4, on the cell surface membrane.
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D051381:Rats; D013189:SRS-A / Q000096:biosynthesis* / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology
D013189:SRS-A