title: On the optimal conditions of LTC4 formation by human eosinophils in vitro.
abstract: The optimal conditions for the -in vitro- LTC4 formation by the human eosinophil, isolated from peripheral blood, have been investigated in detail. LTC4 formation was found strongly Ca2+ and ionophore dependent and was complete after 20 min. Maximal LTC4 production was observed in the presence of 2 mM Ca2+, 10 microM ionophore A23187 and 5 mM glutathione. Addition of arachidonic acid resulted in a significant inhibition of the LTC4-synthesis by human eosinophils. In contrast, the formation of 15-HETE was strongly stimulated by the addition of arachidonic acid. As the LTC4 synthesis was found to be strongly inhibited by the addition of 15(S)-HETE to the incubation medium, this monohydroxy acid may be responsible for the inhibitory activity of arachidonic acid.
mesh_terms: D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002469:Cell Separation; D003545:Cysteine / Q000494:pharmacology; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D005978:Glutathione / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology / Q000276:immunology; D006801:Humans; D007700:Kinetics; D013189:SRS-A / Q000096:biosynthesis / Q000097:blood*
chemical_list: D001095:Arachidonic Acids; D013189:SRS-A; D016718:Arachidonic Acid; D000001:Calcimycin; D005978:Glutathione; D003545:Cysteine; D002118:Calcium