Open AccessLeukotriene C 4 metabolism by hepatoma cells deficient in the uptake of cysteinyl leukotrienes
Author(s) -
WECKBECKER Gisbert,
KEPPLER Dietrich O. R.
Publication year - 1986
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1986.tb09435.x
Subject(s) - leukotriene , leukotriene c4 , leukotriene e4 , metabolism , hepatocyte , extracellular , leukotriene d4 , biochemistry , glutamine , biology , chemistry , amino acid , immunology , in vitro , asthma
Uptake and metabolism of the cysteinyl leukotrienes C 4 and E 4 (LTC 4 and LTE 4 ) were studied in AS‐30D hepatoma cell suspensions and compared with rat hepatocytes. The hepatoma cells were deficient in the uptake of [ 3 H]LTC 4 and [ 3 H]LTE 4 but took up, in control experiments, l ‐[ 14 C]glutamine and [ 14 C]adenosine in a time‐dependent manner. By contrast, isolated hepatocyte suspensions incubated under the same conditions took up [ 3 H]LTC 4 and [ 3 H]LTE 4 as well as l ‐[ 14 C]glutamine and [ 14 C]adenosine. The hepatoma cells deficient in the uptake of cysteinyl leukotrienes metabolized extracellular [ 3 H]LTC 4 to [ 3 H]LTD 4 and to [ 3 H]LTE 4 . Addition of acivicin, an inhibitor of γ‐glutamyltransferase, largely prevented metabolism of [ 3 H]LTC 4 by the hepatoma cells. Sonication of the cells did not enhance the formation of [ 3 H]LTD 4 and [ 3 H]LTE 4 from [ 3 H]LTC 4 . We conclude that ectoenzymes of AS‐30D hepatoma cells catalyze the conversion of LTC 4 to LTE 4 via LTD 4 . As compared to hepatocytes, these neoplastic cells have lost the uptake system for cysteinyl leukotrienes and may serve in studies on leukotriene metabolism by cell‐surface enzymes.