RELEASE OF LEUKOTRIENE-B4 FROM HUMAN-NEUTROPHILS AND ITS RELATIONSHIP TO DE-GRANULATION INDUCED BY N-FORMYL-METHIONYL-LEUCYL-PHENYLALANINE, SERUM-TREATED ZYMOSAN AND THE IONOPHORE A23187

  • 1 January 1983
    • journal article
    • research article
    • Vol. 50  (1) , 65-73
Abstract
The release of leukotriene B4 (LTB4) from human neutrophils and its relationship to degranulation induced by the divalent cation ionophore A23187 [calcimycin], serum-treated zymosan (STZ), N-formyl-methionyl leucyl-phenylalanine (FMLP) and arachidonic acid (AA) were studied. Greatest release of LTB4, measured by specific radioimmunoassay, occurred in response to A23187 (5-10 ng/106 cells); lower concentrations were obtained after incubation with STZ (0.2-0.8 ng/106 cells) and AA (0.3-2.6 ng/106 cells) and low (0.02 ng/106 cells) or not detectable amounts from cells incubated with FMLP. Release of LTB4 induced by STZ, FMLP and submaximal concentrations of A23187 was potentiated by simultaneous addition of AA. Lower amounts (0.06-0.3 ng/106 cells) of thromboxane B2 (TXB2) were also released by these stimuli, this release of TXB2 was not potentiated by exogenous AA. The secretion of .beta.-glucuronidase induced by A23187, STZ and FMLP was not quantitatively related to release of LTB4 or TXB2 and was not potentiated by exogenous AA. FMLP induced degranulation was cytochalasin B (Cyt B)-dependent; LTB4 release in response to this stimulus was only marginally increased by pretreatment of the cells with Cyt B. Apparently, LTB4 does not mediate degranulation induced by these stimuli.