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Control of cytoplasmic pH by Na + /H + exchange in rat peritoneal macrophages activated with phorbol ester
Author(s) -
Rotstein Ori D.,
Houston Kimberly,
Grinstein Sergio
Publication year - 1987
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(87)80150-3
Subject(s) - antiporter , amiloride , chemistry , phorbol , intracellular ph , sodium–hydrogen antiporter , cytoplasm , biophysics , ion transporter , biochemistry , nuclear chemistry , sodium , membrane , intracellular , biology , signal transduction , protein kinase c , organic chemistry
The mechanisms underlying cytoplasmic pH (pH i ) regulation in elicited rat peritoneal macrophages were investigated by electronic sizing and fluorescence determinations. Acid‐loaded cells rapidly regained normal pH i by means of an amiloride‐sensitive Na + /H + exchange. When stimulated by 12‐ O ‐tetradecanoyl phorbol 13‐acetate, macrophages displayed a biphasic pH i change: a marginal acidification followed by an alkalinization. The latter results from activation of Na + /H + exchange, since it is Na + ‐dependent and prevented by amiloride. When the antiport is inhibited, the full magnitude of the initial acidification can be appreciated. This acidification is independent of the nature of the ionic composition of the medium and probably reflects accumulation of protons generated during the metabolic burst. Under physiological conditions, these protons are rapidly extruded by the Na + /H + antiport.