Premium
Glutathione metabolism in activated human neutrophils: stimulation of glutathione synthesis and consumption of glutathione by reactive oxygen species
Author(s) -
BILZER M.,
LAUTERBURG B.H.
Publication year - 1991
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1991.tb01376.x
Subject(s) - glutathione , buthionine sulfoximine , chemistry , cysteine , glutathione reductase , biochemistry , glutathione disulfide , intracellular , reactive oxygen species , metabolism , catabolism , enzyme , glutathione peroxidase
. Since glutathione (GSH) is involved in the modulation of the function of polymorphonuclear leucocytes (PMN) such as phagocytosis and production of reactive oxygen species, the metabolism of GSH was studied in human PMN. The concentration of GSH in resting PMN amounted to 13.3 nmol 10 ‐7 PMN and remained stable over 100 min of incubation. Upon activation of PMN with phorbol myristate acetate intracellular GSH decreased to 50% of the resting concentration within 80 min. In the presence of buthionine sulfoximine, which inhibits the synthesis of GSH, the depletion of intracellular GSH was dramatically accelerated, indicating that activation of PMN is associated with a marked stimulation of GSH synthesis. Since a similar depletion of GSH was seen in the presence of propargylglycine, an inhibitor of the cystathionine pathway, most of the cysteine required for the resynthesis of GSH must originate from methionine and not from cysteine generated by the catabolism of GSH. Further studies showed that GSH is sequentially oxidized by O 2 ‐ and HOCl, first to GSSG and then to an unidentified compound, most likely a chloramine. In the presence of an adequate supply of GSH and NADPH which is required for the reduction of GSSG ‐by glutathione reductase this further oxidation of GSSG was prevented. Thus, the highly toxic HOCl generated by PMN can be detoxified by the glutathione reductase system. The capacity of PMN to re‐synthesize GSH may be an important determinant of PMN function.