期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1982
卷号:79
期号:16
页码:4838-4842
DOI:10.1073/pnas.79.16.4838
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Slow reacting substances (leukotrienes C4, D4, E4) are synthesized in vivo by a combination of two previously unrelated pathways: lipoxygenase oxygenation of arachidonic acid and the glutathione detoxification pathway. Enzymes involved in the latter pathway (glutathione transferase [RX: glutathione R-transferase, EC 2.5.1.18 ]; gamma-glutamyltransferase [(5-glutamyl)-peptide: amino acid 5-glutamyltransferase, EC 2.3.2.2 ] ) have been investigated in guinea pig lung and rat basophilic leukemia (RBL-1) cells. We report data on levels of enzymic activity both before and during the release of slow reacting substances. Both glutathione transferase and gamma-glutamyltransferase are present in significant quantities in guinea pig lung and RBL-1 cells. A model for the changes in gamma-glutamyltransferase during leukotriene release is proposed for the cell line, and differences from the guinea pig lung system are reported. Leukotriene C4 is converted to the more potent leukotriene D4 by the action of gamma-glutamyltransferase on guinea pig ileum during bioassay. gamma-Glutamyltransferase may represent a control feature in the biosynthesis of leukotriene D4, and thus be involved in leukotriene-induced bronchoconstriction in the lung.