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Coupling of polyphosphoinositide breakdown with calcium efflux in formyl‐methionyl‐leucyl‐phenylalanine‐stimulated rabbit neutrophils
Author(s) -
Yano Koh,
Nakashima Shigeru,
Nozawa Yoshinori
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)81028-x
Subject(s) - efflux , arachidonic acid , phosphatidylinositol , chemistry , phenylalanine , stimulation , biochemistry , calcium , glycerol , enzyme , endocrinology , biology , amino acid , signal transduction , organic chemistry
Exposure of rabbit neutrophils to formyl‐methionyl‐leucyl‐phenylalanine (FMLP) induced the efflux of 45 Ca 2+ from pre‐labeled cells which was almost complete within 30 s. On the other hand, FMLP‐induced 45 Ca 2+ influx did not become apparent until 60 s after stimulation. When [ 3 H]arachidonic acid‐labeled neutrophils were stimulated with FMLP, the radioactivities in phosphatidylinositol 4,5‐biphosphate (TPI) and phosphatidylinositol 4‐phosphate (DPI) significantly decreased in parallel with the induction of 45 Ca 2+ efflux. In contrast, degradation of polyphosphoinositides in [ 3 H]glycerol‐labeled neutrophils was not significant until 60 s. Taken together, these results indicate that the early degradation of polyphosphoinositides, especially of those rich in arachidonic acid is closely associated with the initial efflux of calcium in FMLP‐stimulated rabbit neutrophils. The study of resynthesis of polyphosphoinositides by measuring 32 P i incorporation into these lipids is also presented.