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Protamine‐induced permeability changes in the neutrophil plasma membrane as the basis of activation of exocytosis
Author(s) -
Elferink J. G. R.
Publication year - 1992
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290100107
Subject(s) - exocytosis , protamine , biophysics , chemistry , extracellular , membrane , biochemistry , biology , heparin
Protamine induces a gradual change in plasma membrane permeability in rabbit neutrophils, which is evident from the increase of indol fluorescence, and the leakage of quin2 from quin2‐loaded neutrophils. The influx of extracellular Ca 2+ into the neutrophil provides an explanation for exocytosis which occurs in the presence of Ca 2+ and protamine. The dependence of exocytosis on Ca 2+ concentration follows the same pattern as is observed in neutrophils permeabilized by other means. In the absence of Ca 2+ , and in the presence of protamine, La 3+ has an activating effect on exocytosis. At higher concentrations La 3+ inhibits exocytosis that occurs in the presence of Ca 2+ and protamine, as do some other metal ions. The resemblance between the membrane effects of a number of toxins, as reported in literature, and protamine‐induced membrane damage suggests that they occur via the same mechanism.