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Leukotriene D 4 ‐induced increases in the cytoplasmic pH of human myelocytic leukocytes
Author(s) -
Baud Laurent,
Healy Ann,
Cragoe Edward J.,
Goetzl Edward J.,
Koo Catherine H.
Publication year - 1988
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041360220
Subject(s) - intracellular , leukotriene d4 , antiporter , chemistry , intracellular ph , leukotriene c4 , leukotriene , leukotriene b4 , amiloride , biochemistry , biophysics , sodium , biology , membrane , inflammation , immunology , antagonist , receptor , organic chemistry , asthma
The effects of leukotriene D 4 on the intracellular pH of human myelocytes, derived from cultured HL‐60 cells by dimethylsulfoxide‐induced differentiation, were quantified with the fluorescent indicator 2′,7′‐bis‐(2‐carboxy‐ethyl)‐5,6‐carboxyfluorescein. Leukotriene D 4 , but not C 4 or E 4 , increased intracellular pH optimally by 3 min with a half‐maximal effect at 1–2 nM. The increases in intracellular pH stimulated by leukotriene D 4 were prevented by pretreatment of myelocytes with leukotriene D 4 but not peptide chemotactic factors. Analogs of amiloride that inhibit selectively the Na + /H + antiport also prevented the intracellular alkalinization induced by leukotriene D 4 . The rate of recovery of intracellular pH after an acid load with 30 mM sodium propionate was approximately 30% higher at each level of intracellular pH for myelocytes exposed to leukotriene D 4 than for those challenged in buffer alone. The increase elicited by leukotriene D 4 in the adherence of myelocytic leukocytes to surfaces thus is associated with an enhanced sensitivity of the Na + /H + antiport to intracellular pH, that is, not coupled to an earlier rise in the cytosolic level of Ca +2 .